An until hierarchy for temporal logic
逻辑翻译学视角下科技文本中后置定语的翻译策略研究——以《气候变化和空..
Translation Strategies for Translating Postmodifiers in Scientific Text from the Perspective of Logic Translation Theory: A Case Study of the Translation of Climate Changeand Air PollutionByZhang XiaojieUnder the Supervision ofAssociate Professor Zheng YouqiSubmitted in Partial Fulfillment of the RequirementsFor the Degree of Master of Translation and InterpretingDepartment of EnglishCollege of Liberal ArtsNanjing University of Information Science & TechnologyJune, 2019AcknowledgementsI would like to express my sincere appreciation to those who have given me invaluable help during the writing of this report.First and foremost, my heartfelt gratitude goes to my supervisor, Associate Professor Zheng Youqi, for his constant encouragement during these two years and instructive advice on this report. Associate Professor Zheng has offered a lot of valuable suggestions during the preparation for the report. He has also revised my draft carefully and offered clear instruction. Without his patient instruction and insightful criticism, it would not have been possible for me to complete this report.In addition, I wish to take this opportunity to express my deep gratitude to all the teachers who have taught me for their patient instructions in many courses and their precious suggestions. What I learned from their classes has helped me lay the foundation for this report.Last but not least, my gratitude extends to my beloved parents for providing support and care for me in my whole life. They have given me strong support when I was confronted with difficulties in writing the report.ContentsAbstract ........................................................................................................................ I II 摘要 (V)Chapter One Introduction (1)1.1 Research Background (1)1.2 Motivation and Significance of the Research (2)1.3 Layout of the Report (3)Chapter Two Task Description (5)2.1 Project Profile (5)2.2 Process of the Project (5)2.2.1 Preparation for Translation (5)2.2.2 Process of Translation (6)2.2.3 Revision after Translation (7)Chapter Three Literature Review (8)3.1 Differences of Attribute between Chinese and English (8)3.2 Translation Strategies for Postmodifier in English. (9)Chapter Four Theoretical Framework (11)4.1 Development of the Logic Translation Theory (11)4.2 Application of the Logic Translation Theory in the Translation of thePostmodifier (12)Chapter Five A Case Study (14)5.1 Translation of the Adjective Phrase as Postmodifier (14)5.1.1 Inversion (14)5.1.2 Division (15)5.2 Translation of the Non-Finite Verb as Postmodifier (16)5.2.1 Inversion (17)5.2.2 Division (18)5.2.3 Amplification (19)5.3 Translation of the Attributive Clause as Postmodifier (20)5.3.1 Inversion (20)5.3.2 Amplification (21)5.3.3 Division (23)5.4 Translation of the Prepositional Phrase as Postmodifier. (24)5.4.1 Inversion (24)5.4.2 Conversion (25)5.4.3 Amplification (25)5.4.4 Division (26)Chapter Six Conclusion (28)References (30)Appendix 1 Source Text and Target Text (32)Appendix II Technical Terms (94)攻读学位期间的研究成果 (95)AbstractThere are many postmodifiers in English for Science and Technology (EST), which imply the logic in the original text. EST is characterized by strong professionalism, compact structure, strict logic, concise writing, objective expression, exact content, a large amount of information and emphasis on the existence of facts. Therefore, translators must restore its logical rigor with accurate and standardized expressions. In this translation task, Chapter One, Chapter Two and Chapter Three are selected as the source text from the book Climate Change and Air Pollution. Today, climate change and air pollution are major concerns around the world. These chapters describe the history and the impact of climate change and air pollution, and the international conferences held to address the problems caused by climate change. This report lists four forms of English postmodifiers from the three chapters, namely, adjective phrases as postmodifiers, non-predicate verb phrases as postmodifiers, attributive clauses as postmodifiers, and prepositional phrases as postmodifiers. Under the guidance of logic translation theory, four common translation strategies are used in the translation of these four kinds of postmodifiers, namely conversion, amplification, inversion and division. Logic plays an important role in the process of interlingual transformation, which runs through the process of translation. From words, sentences, paragraphs to the whole text, the more accurately the translator grasps the semantic logic of the source language, the easier it is to understand the meaning of the original text. When a translation is organized, it is the key to express the original meaning accurately and smoothly. Only in this way can the translator successfully transfer source language thinking to target language thinking, and skillfully use the logic of the target language to organize the translation.The report is divided into six chapters. The first chapter demonstrates the research background, the motivation and significance of the research and the layout of the report. The second chapter mainly describes the process of the project. Theliterature review is mentioned in the third chapter, including the differences of attribute between Chinese and English and the translation strategies of postmodifiers in English. The fourth chapter depicts the development and application of the logic translation theory. The fifth chapter, as the main body of the report, poses some proper translation strategies to solve different kinds of problems. The last chapter is a summary of the study.Key Words: Logic translation theory; Postmodifier; Translation strategy; Climate Change and Air Pollution摘要科技英语中后置定语出现频繁，体现原文的逻辑思维。
翻译的外文文献
The Beginning of Model Checking:A Personal PerspectiveE.Allen Emerson1,21.Department of Computer Sciencesputer Engineering Research CenterThe University of Texas at Austin,Austin TX78712,USAAbstract.Model checking provides an automated method for verify-ing concurrent systems.Correctness specifications are given in tempo-ral logic.The method hinges on an efficient andflexible graph-theoreticreachability algorithm.At the time of its introduction in the early1980’s,the prevailing paradigm for verification was a manual one of proof-theoretic reasoning using formal axioms and inference rules oriented to-wards sequential programs.The need to encompass concurrent programs,the desire to avoid the difficulties with manual deductive proofs,and thesmall model theorem for temporal logic motivated the development ofmodel checking.Keywords:model checking,model-theoretic,synthesis,history,origins1IntroductionIt has long been known that computer software programs,computer hardware designs,and computer systems in general exhibit errors.Working programmers may devote more than half of their time on testing and debugging in order to increase reliability.A great deal of research effort has been and is devoted to developing improved testing methods.Testing successfully identifies many significant errors.Yet,serious errors still afflict many computer systems including systems that are safety critical,mission critical,or economically vital.The US National Institute of Standards and Technology has estimated that programming errors cost the US economy$60B annually[Ni02].Given the incomplete coverage of testing,alternative approaches have been sought.The most promising approach depends on the fact that programs and more generally computer systems may be viewed as mathematical objects with behavior that is in principle well-determined.This makes it possible to specify using mathematical logic what constitutes the intended(correct)behavior.Then one can try to give a formal proof or otherwise establish that the program meets This work was supported in part by National Science Foundation grants CCR-009-8141&CCR-020-5483and funding from Fujitsu Labs of America. email:emerson@ URL:/∼emerson/its specification.This line of study has been active for about four decades now. It is often referred to as formal methods.The verification problem is:Given program M and specification h determine whether or not the behavior of M meets the specification h.Formulated in terms of Turing Machines,the verification problem was considered by Turing[Tu36]. Given a Turing Machine M and the specification h that it should eventually halt (say on blank input tape),one has the halting problem which is algorithmically unsolvable.In a later paper[Tu49]Turing argued for the need to give a(manual) proof of termination using ordinals,thereby presaging work by Floyd[Fl67]and others.The model checking problem is an instance of the verification problem.Model checking provides an automated method for verifying concurrent(nominally)finite state systems that uses an efficient andflexible graph search,to determine whether or not the ongoing behavior described by a temporal property holds of the system’s state graph.The method is algorithmic and often efficient because the system isfinite state,despite reasoning about infinite behavior.If the answer is yes then the system meets its specification.If the answer is no then the system violates its specification;in practice,the model checker can usually produce a counterexample for debugging purposes.At this point it should be emphasized that the verification problem and the model checking problem are mathematical problems.The specification is for-mulated in mathematical logic.The verification problem is distinct from the pleasantness problem[Di89]which concerns having a specification capturing a system that is truly needed and wanted.The pleasantness problem is inherently pre-formal.Nonetheless,it has been found that carefully writing a formal specifi-cation(which may be the conjunction of many sub-specifications)is an excellent way to illuminate the murk associated with the pleasantness problem.At the time of its introduction in the early1980’s,the prevailing paradigm for verification was a manual one of proof-theoretic reasoning using formal axioms and inference rules oriented towards sequential programs.The need to encom-pass concurrent programs,and the desire to avoid the difficulties with manual deductive proofs,motivated the development of model checking.In my experience,constructing proofs was sufficiently difficult that it did seem there ought to be an easier alternative.The alternative was suggested by temporal logic.Temporal logic possessed a nice combination of expressiveness and decidability.It could naturally capture a variety of correctness properties, yet was decidable on account of the“Small”Finite Model Theorem which en-sured that any satisfiable formula was true in somefinite model that was small. It should be stressed that the Small Finite Model Theorem concerns the satisfi-ability problem of propositional temporal logic,i.e.,truth in some state graph. This ultimately lead to model checking,i.e.,truth in a given state graph.The origin and development of model checking will be described below.De-spite being hampered by state explosion,over the past25years model checking has had a substantive impact on program verification efforts.Formal verification2has progressed from discussions of how to manually prove programs correct to the routine,algorithmic,model-theoretic verification of many programs.The remainder of the paper is organized as follows.Historical background is discussed in section2largely related to verification in the Floyd-Hoare paradigm; protocol verification is also considered.Section3describes temporal logic.A very general type of temporal logic,the mu-calculus,that defines correctness in terms offixpoint expressions is described in section4.The origin of model checking is described in section5along with some relevant personal influences on me.A discussion of model checking today is given in section6.Some concluding remarks are made in section7.2Background of Model CheckingAt the time of the introduction of model checking in the early1980’s,axiomatic verification was the prevailing verification paradigm.The orientation of this paradigm was manual proofs of correctness for(deterministic)sequential pro-grams,that nominally started with their input and terminated with their out-put.The work of Floyd[Fl67]established basic principles for proving partial correctness,a type of safety property,as well as termination and total correct-ness,forms of liveness properties.Hoare[Ho69]proposed an axiomatic basis for verification of partial correctness using axioms and inference rules in a formal deductive system.An important advantage of Hoare’s approach is that it was compositional so that the proof a program was obtained from the proofs of its constituent subprograms.The Floyd-Hoare framework was a tremendous success intellectually.It en-gendered great interest among researchers.Relevant notions from logic such as soundness and(relative)completeness as well as compositionality were in-vestigated.Proof systems were proposed for new programming languages and constructs.Examples of proofs of correctness were given for small programs.However,this framework turned out to be of limited use in practice.It did not scale up to“industrial strength”programs,despite its merits.Problems start with the approach being one of manual proof construction.These are formal proofs that can involve the manipulations of extremely long logical formulae. This can be inordinately tedious and error-prone work for a human.In practice, it may be wholly infeasible.Even if strict formal reasoning were used throughout, the plethora of technical detail could be overwhelming.By analogy,consider the task of a human adding100,000decimal numbers of1,000digits each.This is rudimentary in principle,but likely impossible in practice for any human to perform reliably.Similarly,the manual verification of100,000or10,000or even 1,000line programs by hand is not feasible.Transcription errors alone would be prohibitive.Furthermore,substantial ingenuity may also be required on the part of the human to devise suitable assertions for loop invariants.One can attempt to partially automate the process of proof construction using an interactive theorem prover.This can relieve much of the clerical burden.3However,human ingenuity is still required for invariants and various lemmas. Theorem provers may also require an expert operator to be used effectively.Moreover,the proof-theoretic framework is one-sided.It focuses on providing a way to(syntactically)prove correct programs that are genuinely(semantically) correct.If one falters or fails in the laborious process of constructing a proof of a program,what then?Perhaps the program is really correct but one has not been clever enough to prove it so.On the other hand,if the program is really incorrect,the proof systems do not cater for proving incorrectness.Since in practice programs contain bugs in the overwhelming majority of the cases,the inability to identify errors is a serious drawback of the proof-theoretic approach.It seemed there ought to be a better way.It would be suggested by temporal logic as discussed below.Remark.We mention that the term verification is sometimes used in a specific sense meaning to establish correctness,while the term refutation(or falsification) is used meaning to detect an error.More generally,verification refers to the two-sided process of determining whether the system is correct or erroneous.Lastly,we should also mention in this section the important and useful area of protocol work protocols are commonlyfinite state.This makes it possible to do simple graph reachability analysis to determine if a bad state is accessible(cf.[vB78],[Su78]).What was lacking here was aflexible and expres-sive means to specify a richer class of properties.3Temporal LogicModal and temporal logics provided key inspiration for model checking.Origi-nally developed by philosophers,modal logic deals with different modalities of truth,distinguishing between P being true in the present circumstances,pos-sibly P holding under some circumstances,and necessarily P holding under all circumstances.When the circumstances are points in time,we have a modal tense logic or temporal logic.Basic temporal modalities include sometimes P and always P.Several writers including Prior[Pr67]and Burstall[Bu74]suggested that temporal logic might be useful in reasoning about computer programs.For in-stance,Prior suggested that it could be used to describe the“workings of a digital computer”.But it was the seminal paper of Pnueli[Pn77]that made the crit-ical suggestion of using temporal logic for reasoning about ongoing concurrent programs which are often characterized as reactive systems.Reactive systems typically exhibit ideally nonterminating behavior so that they do not conform to the Floyd-Hoare paradigm.They are also typically non-deterministic so that their non-repeatable behavior was not amenable to testing. Their semantics can be given as infinite sequences of computation states(paths) or as computation trees.Examples of reactive systems include microprocessors, operating systems,banking networks,communication protocols,on-board avion-ics systems,automotive electronics,and many modern medical devices.4Pnueli used a temporal logic with basic temporal operators F(sometimes) and G(always);augmented with X(next-time)and U(until)this is today known as LTL(Linear Time Logic).Besides the basic temporal operators applied to propositional arguments,LTL permitted formulae to be built up by forming nestings and boolean combinations of subformulae.For example,G¬(C1∧C2) expresses mutual exclusion of critical sections C1and C2;formula G(T1⇒(T1U C1)specifies that if process1is in its trying region it remains there until it eventually enters its critical section.The advantages of such a logic include a high degree of expressiveness permit-ting the ready capture of a wide range of correctness properties of concurrent programs,and a great deal offlexibility.Pnueli focussed on a proof-theoretic approach,giving a proof in a deductive system for temporal logic of a small example program.Pnueli does sketch a decision procedure for truth overfinite state graphs.However,the complexity would be nonelementary,growing faster than anyfixed composition of exponential functions,as it entails a reduction to S1S,the monadic Second order theory of1Successor,(or SOLLO;see be-low).In his second paper[Pn79]on temporal logic the focus is again on the proof-theoretic approach.I would claim that temporal logic has been a crucial factor in the success of model checking.We have one logical framework with a few basic temporal operators permitting the expression of limitless specifications.The connection with natural language is often significant as well.Temporal logic made it possible, by and large,to express the correctness properties that needed to be expressed. Without that ability,there would be no reason to use model checking.Alternative temporal formalisms in some cases may be used as they can be more expressive or succinct than temporal logic.But historically it was temporal logic that was the driving force.These alternative temporal formalisms include:(finite state)automata(on infinite strings)which accept infinite inputs by infinitely often entering a desig-nated set of automaton states[Bu62].An expressively equivalent but less succinct formalism is that ofω-regular expressions;for example,ab cωdenotes strings of the form:one a,0or more b s,and infinitely many copies of c;and a property not expressible in LTL(true P)ωensuring that at every even moment P holds. FOLLO(First Order Language of Linear Order)which allows quantification over individual times,for example,∀i≥0Q(i);and SOLLO(Second Order Language of Linear Order)which also allows quantification over sets of times corresponding to monadic predicates such as∃Q(Q(0)∧∀i≥0(Q(i)⇒Q(i+1)).1These alterna-tives are sometimes used for reasons of familiarity,expressiveness or succinctness. LTL is expressively equivalent to FOLLO,but FOLLO can be nonelementarily more succinct.This succinctness is generally found to offer no significant practi-cal advantage.Moreover,model checking is intractably(nonelementarily)hard for FOLLO.Similarly,SOLLO is expressively equivalent toω−regular expres-sions but nonelementarily more succinct.See[Em90]for further discussion.1Technically,the latter abbreviates∃Q(Q(0)∧∀i,j≥0(i<j∧¬∃k(i<k<j))⇒(Q(i)⇒Q(j)).5Temporal logic comes in two broad styles.A linear time LTL assertion h is interpreted with respect to a single path.When interpreted over a program there is an implicit universal quantifications over all paths of the program.An assertion of a branching time logic is interpreted over computation trees.The universal A (for all futures)and existential E(for some future)path quantifiers are important in this context.We can distinguish between AF P(along all futures,P eventually holds and is thus inevitable))and EF P(along some future,P eventually holds and is thus possible).One widely used branching time logic is CTL(Computation Tree Logic)(cf. [CE81]).Its basic temporal modalities are A(for all futures)or E(for some fu-ture)followed by one of F(sometime),G(always),X(next-time),and U(until); compound formulae are built up from nestings and propositional combinations of CTL subformulae.CTL derives from[EC80].There we defined the precursor branching time logic CTF which has path quantifiers∀fullpath and∃fullpath, and is very similar to CTL.In CTF we could write∀fullpath∃state P as well as ∃fullpath∃state P These would be rendered in CTL as AF P and EF P,respec-tively.The streamlined notation was derived from[BMP81].We also defined a modal mu-calculus FPF,and then showed how to translate CTF into FPF. The heart of the translation was characterizing the temporal modalities such as AF P and EF P asfixpoints.Once we had thefixpoint characterizations of these temporal operators,we were close to having model checking.CTL and LTL are of incomparable expressive power.CTL can assert the existence of behaviors,e.g.,AGEF start asserts that it is always possible to re-initialize a circuit.LTL can assert certain more complex behaviors along a computation,such as GF en⇒F ex relating to fairness.(It turns out this formula is not expressible in CTL,but it is in“FairCTL”[EL87])The branching time logic CTL*[EH86]provides a uniform framework that subsumes both LTL and CTL,but at the higher cost of deciding satisfiability.There has been an ongoing debate as to whether linear time logic or branching time logic is better for program reasoning(cf.[La80],[EH86],[Va01]).Remark.The formal semantics of temporal logic formulae are defined with respect to a(Kripke)structure M=(S,S0,R,L)where S is a set of states,S0 comprises the initial states,R⊆S×S is a total binary relation,and L is a labelling of states with atomic facts(propositions)true there.An LTL formula h such as F P is defined over path x=t0,t1,t2...through M by the rule M,x|= F P iff∃i≥0P∈L(t i).Similarly a CTL formula f such as EGP holds of a state t0,denoted M,t0|=EGP,iffthere exists a path x=t0,t1,t2,...in M such that∀i≥0P∈L(t i).For LTL h,we define M|=h ifffor all paths x starting in S0,M,x|=h.For CTL formula f we define M|=f ifffor each s∈S0,M,s|=f.A structure is also known as a state graph or state transition graph or transition system.See[Em90]for details.64The Mu-calculusThe mu-calculus may be viewed as a particular but very general temporal logic. Some formulations go back to the work of de Bakker and Scott[deBS69];we deal specifically with the(propositional or)modal mu-calculus(cf.[EC80],[Ko83]). The mu-calculus provides operators for defining correctness properties using re-cursive definitions plus leastfixpoint and greatestfixpoint operators.Leastfix-points correspond to well-founded or terminating recursion,and are used to capture liveness or progress properties asserting that something does happen. Greatestfixpoints permit infinite recursion.They can be used to capture safety or invariance properties.The mu-calculus is very expressive and veryflexible.It has been referred to as a“Theory of Everything”.The formulae of the mu-calculus are built up from atomic proposition con-stants P,Q,...,atomic proposition variables Y,Z,...,propositional connectives ∨,∧,¬,and the leastfixpoint operator,µas well as the greatestfixpoint opera-tor,ν.Eachfixpoint formula such asµZ.τ(Z)should be syntactically monotone meaning Z occurs under an even number of negations,and similarly forν.The mu-calculus is interpreted with respect to a structure M=(S,R,L). The power set of S,2S,may be viewed as the complete lattice(2S,S,∅,⊆,∪,∩).Intuitively,each(closed)formula may be identified with the set of states of S where it is true.Thus,false which corresponds to the empty set is the bottom element,true which corresponds to S is the top element,and implication (∀s∈S[P(s)⇒Q(s)])which corresponds to simple set-theoretic containment (P⊆Q)provides the partial ordering on the lattice.An open formulaτ(Z) defines a mapping from2S→2S whose value varies as Z varies.A givenτ: 2S→2S is monotone provided that P⊆Q impliesτ(P)⊆τ(Q).Tarski-Knaster Theorem.(cf.[Ta55],[Kn28])Letτ:2S→2S be a monotone functional.Then(a)µY.τ(Y)=∩{Y:τ(Y)=Y}=∩{Y:τ(Y)⊆Y},(b)νY.τ(Y)=∪{Y:τ(Y)=Y}=∪{Y:τ(Y)⊇Y},(c)µY.τ(Y)=∪iτi(false)where i ranges over all ordinals of cardinality at mostthat of the state space S,so that when S isfinite i ranges over[0:|S|],and (d)νY.τ(Y)=∩iτi(true)where i ranges over all ordinals of cardinality at mostthat of the state space S,so that when S isfinite i ranges over[0:|S|].Consider the CTL property AF P.Note that it is afixed point orfixpoint of the functionalτ(Z)=P∨AXZ.That is,as the value of the input Z varies,the value of the outputτ(Z)varies,and we have AF P=τ(AF P)=P∨AXAF P. It can be shown that AF P is the leastfixpoint ofτ(Z),meaning the set of states associated with AF P is a subset of the set of states associated with Z,for any fixpoint Z=τ(Z).This might be denotedµZ.Z=τ(Z).More succinctly,we normally write justµZ.τ(Z).In this case we have AF P=µZ.P∨AXZ.We can get some intuition for the the mu-calculus by noting the following fixpoint characterizations for CTL properties:7EF P=µZ.P∨EXZAGP=νZ.P∧AXZAF P=µZ.P∨AXZEGP=νZ.P∧EXZA(P U Q)=µZ.Q∨(P∧AXZ)E(P U Q)=µZ.Q∨(P∧EXZ)For all these properties,as we see,thefixpoint characterizations are simple and plausible.It is not too difficult to give rigorous proofs of their correctness (cf.[EC80],[EL86]).We emphasize that the mu-calculus is a rich and powerful formalism;its formulae are really representations of alternatingfinite state au-tomata on infinite trees[EJ91].Since even such basic automata as deterministic finite state automata onfinite strings can form quite complex“cans of worms”, we should not be so surprised that it is possible to write down highly inscrutable mu-calculus formulae for which there is no readily apparent intuition regard-ing their intended meaning.The mu-calculus has also been referred to as the “assembly language of program logics”reflecting both its comprehensiveness and potentially intricate syntax.On the other hand,many mu-calculus char-acterizations of correctness properties are elegant due to its simple underlying mathematical organization.In[EL86]we introduced the idea of model checking for the mu-calculus in-stead of testing satisfiability.We catered for efficient model checking in fragments of the the mu-calculus.This provides a basis for practical(symbolic)model checking algorithms.We gave an algorithm essentially of complexity n d,where d is the alternation depth reflecting the number of significantly nested least and greatestfixpoint operators.We showed that common logics such as CTL,LTL, and CTL*were of low alternation depth d=1or d=2.We also provided succinctfixpoint characterizations for various natural fair scheduling criteria.A symbolic fair cycle detection method,known as the“Emerson-Lei”algorithm, is comprised of a simplefixpoint characterization plus the Tarski-Knaster theo-rem.It is widely used in practice even though it has worst case quadratic cost. Empirically,it usually outperforms alternatives.5The Origin of Model CheckingThere were several influences in my personal background that facilitated the de-velopment of model checking.In1975Zohar Manna gave a talk at the University of Texas onfixpoints and the Tarski-Knaster Theorem.I was familiar with Di-jkstra’s book[Di76]extending the Floyd-Hoare framework with wlp the weakest liberal precondition for partial correctness and wp the weakest precondition for to-tal correctness.It turns out that wlp and wp may be viewed as modal operators, for which Dijkstra implicitly gavefixpoint characterizations,although Dijkstra did not favor this viewpoint.Basu and Yeh[BY75]at Texas gavefixpoint char-acterizations of weakest preconditions for while loops.Ed Clarke[Cl79]gave similarfixpoint characterizations for both wp and wlp for a variety of control structures.8I will now describe how model checking originated at Harvard University.In prior work[EC80]we gavefixpoint characterizations for the main modalities of a logic that was essentially CTL.These would ultimately provide thefirst key ingredient of model checking.Incidentally,[EC80]is a paper that could very well not have appeared.Some-how the courier service delivering the hard-copies of the submission to Amster-dam for the program chair at CWI(Dutch for“Center for Mathematics and Computer Science”)sent the package in bill-the-recipient mode.Fortunately, CWI was gracious and accepted the package.All that remained to undo this small misfortune was to get an overseas bank draft to reimburse them.The next work,entitled“Design and Synthesis of Synchronization Skeletons using Branching Time Logic”,was devoted to program synthesis and model checking.I suggested to Ed Clarke that we present the paper,which would be known as[CE81],at the IBM Logics of Programs workshop,since he had an invitation to participate.Both the idea and the term model checking were introduced by Clarke and Emerson in[CE81].Intuitively,this is a method to establish that a given program meets a given specification where:–The program defines afinite state graph M.–M is searched for elaborate patterns to determine if the specification f holds.–Pattern specification isflexible.–The method is efficient in the sizes of M and,ideally,f.–The method is algorithmic.–The method is practical.The conception of model checking was inspired by program synthesis.I was interested in verification,but struck by the difficulties associated with manual proof-theoretic verification as noted above.It seemed that it might be possible to avoid verification altogether and mechanically synthesize a correct program directly from its CTL specification.The idea was to exploit the small model property possessed by certain decidable temporal logics:any satisfiable formula must have a“small”finite model of size that is a function of the formula size. The synthesis method would be sound:if the input specification was satisfiable, it built afinite global state graph that was a model of the specification,from which individual processes could be extracted The synthesis method should also be complete:If the specification was unsatisfiable,it should say so.Initially,it seemed to me technically problematic to develop a sound and complete synthesis method for CTL.However,it could always be ensured that an alleged synthesis method was at least sound.This was clear because given anyfinite model M and CTL specification f one can algorithmically check that M is a genuine model of f by evaluating(verifying)the basic temporal modal-ities over M based on the Tarski-Knaster theorem.This was the second key ingredient of model posite temporal formulae comprised of nested subformulae and boolean combinations of subformulae could be verified by re-cursive descent.Thus,fixpoint characterizations,the Tarski-Knaster theorem, and recursion yielded model checking.9Thus,we obtained the model checking framework.A model checker could be quite useful in practice,given the prevalence offinite state concurrent systems. The temporal logic CTL had theflexibility and expressiveness to capture many important correctness properties.In addition the CTL model checking algorithm was of reasonable efficiency,polynomial in the structure and specification sizes. Incidentally,in later years we sometimes referred to temporal logic model check-ing.The crucial roles of abstraction,synchronization skeletons,andfinite state spaces were discussed in[CE81]:The synchronization skeleton is an abstraction where detail irrelevant to synchronization is suppressed.Most solutions to synchronization prob-lems are in fact given as synchronization skeletons.Because synchronization skeletons are in generalfinite state...proposi-tional temporal logic can be used to specify their properties.Thefinite model property ensures that any program whose synchroniza-tion properties can be expressed in propositional temporal logic can be realized by afinite state machine.Conclusions of[CE81]included the following prognostications,which seem to have been on target:[Program Synthesis]may in the long run be quite practical.Much addi-tional research will be needed,however,to make it feasible in practice....We believe that practical[model checking]tools could be developed in the near future.To sum up,[CE81]made several contributions.It introduced model check-ing,giving an algorithm of quadratic complexity O(|f||M|2).It introduced the logic CTL.It gave an algorithmic method for concurrent program synthesis(that was both sound and complete).It argued that most concurrent systems can be abstracted tofinite state synchronization skeletons.It described a method for efficiently model checking basic fairness using strongly connected components. An NP-hardness result was established for checking certain assertions in a richer logic than CTL.A prototype(and non-robust)model checking tool BMoC was developed,primarily by a Harvard undergraduate,to permit verification of syn-chronization protocols.A later paper[CES86]improved the complexity of CTL model checking to linear O(|f||M|).It showed how to efficiently model check relative to uncondi-tional and weak fairness.The EMC model checking tool was described,and a version of the alternating bit protocol verified.A general framework for efficiently model checking fairness properties was given in[EL87],along with a reduction showing that CTL*model checking could be done as efficiently as LTL model checking.Independently,a similar method was developed in France by Sifakis and his student[QS82].Programs were interpreted over transition systems.A branching10。
英语单词
1. Typical of the grassland dwellers of the continent is the American antelope, or pronghorn. 美洲羚羊，或称叉角羚，是该大陆典型的草原动物。
2. Of the millions who saw Haley’s comet in 1986, how many people will live long enough to see it return in the twenty-first century. 1986年看见哈雷慧星的千百万人当中，有多少人能够长寿到足以目睹它在二十一世纪的回归呢？3. Anthropologists have discovered that fear, happiness, sadness, and surprise are universally reflected in facial expressions.人类学家们已经发现，恐惧，快乐，悲伤和惊奇都会行之于色，这在全人类是共通的。
4. Because of its irritating effect on humans, the use of phenol as a general antiseptic has been largely discontinued. 由于苯酚对人体带有刺激性作用，它基本上已不再被当作常用的防腐剂了。
5. In group to remain in existence, a profit-making organization must, in the long run, produce something consumers consider useful or desirable.任何盈利组织若要生存，最终都必须生产出消费者可用或需要的产品。
6. The greater the population there is in a locality, the greater the need there is for water, transportation, and disposal of refuse. 一个地方的人口越多，其对水，交通和垃圾处理的需求就会越大。
北航翻译硕士指定参考书目：[翻译研究词典]术语翻译-打印下来直接背
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Fidelitat
忠信
Fidelity
忠信
F.I.T.(In ternatio nal Federati on
国际译联
of Tran slators)
Foreig nizing Tran slati on
异化翻译
Form-derivative Forms
派生形式的形式
Form-focused Texts
文化置换
Decision-making,Translation as
翻译即抉择
Definitions of Translation
翻译定义
Degree of Differe ntiati on
区分度
Descriptive Tran slati on Studies
(DTS
描写翻译研究；描写翻译学
Diagrammatic Tran slati on
逆转换
Back-tra nslatio n
回译
Bilatral In terpreti ng
双边传译
Bilingual Corporal
双语语料库
Bi-text
双文本
Bla nk Spaces
空位
Bla nk Verse Tran slati on
无韵体翻译
Borrow ing
借用
Calque
仿造
CAT
Correspondences,Hierarchy of
对应层级
Court In terpret ing
法庭传译
Covert Tran slati on
隐型翻译
Cross-temporal Theories of
Tran slati on
自然语言处理及计算语言学相关术语中英对译表三_计算机英语词汇
multilingual processing system 多语讯息处理系统multilingual translation 多语翻译multimedia 多媒体multi-media communication 多媒体通讯multiple inheritance 多重继承multistate logic 多态逻辑mutation 语音转换mutual exclusion 互斥mutual information 相互讯息nativist position 语法天生假说natural language 自然语言natural language processing (nlp) 自然语言处理natural language understanding 自然语言理解negation 否定negative sentence 否定句neologism 新词语nested structure 崁套结构network 网络neural network 类神经网络neurolinguistics 神经语言学neutralization 中立化n-gram n-连词n-gram modeling n-连词模型nlp (natural language processing) 自然语言处理node 节点nominalization 名物化nonce 暂用的non-finite 非限定non-finite clause 非限定式子句non-monotonic reasoning 非单调推理normal distribution 常态分布noun 名词noun phrase 名词组np (noun phrase) completeness 名词组完全性object 宾语{语言学}/对象{信息科学}object oriented programming 对象导向程序设计[面向对向的程序设计]official language 官方语言one-place predicate 一元述语on-line dictionary 线上查询词典 [联机词点]onomatopoeia 拟声词onset 节首音ontogeny 个体发生ontology 本体论open set 开放集operand 操作数 [操作对象]optimization 最佳化 [最优化]overgeneralization 过度概化overgeneration 过度衍生paradigmatic relation 聚合关系paralanguage 附语言parallel construction 并列结构parallel corpus 平行语料库parallel distributed processing (pdp) 平行分布处理paraphrase 转述 [释意;意译;同意互训]parole 言语parser 剖析器 [句法剖析程序]parsing 剖析part of speech (pos) 词类particle 语助词part-of relation part-of 关系part-of-speech tagging 词类标注pattern recognition 型样识别p-c (predicate-complement) insertion 述补中插pdp (parallel distributed processing) 平行分布处理perception 知觉perceptron 感觉器 [感知器]perceptual strategy 感知策略performative 行为句periphrasis 用独立词表达perlocutionary 语效性的permutation 移位petri net grammar petri 网语法philology 语文学phone 语音phoneme 音素phonemic analysis 因素分析phonemic stratum 音素层phonetics 语音学phonogram 音标phonology 声韵学 [音位学;广义语音学] phonotactics 音位排列理论phrasal verb 词组动词 [短语动词]phrase 词组 [短语]phrase marker 词组标记 [短语标记]pitch 音调pitch contour 调形变化pivot grammar 枢轴语法pivotal construction 承轴结构plausibility function 可能性函数pm (phrase marker) 词组标记 [短语标记] polysemy 多义性pos-tagging 词类标记postposition 方位词pp (preposition phrase) attachment 介词依附pragmatics 语用学precedence grammar 优先级语法precision 精确度predicate 述词predicate calculus 述词计算predicate logic 述词逻辑 [谓词逻辑]predicate-argument structure 述词论元结构prefix 前缀premodification 前置修饰preposition 介词prescriptive linguistics 规定语言学 [规范语言学] presentative sentence 引介句presupposition 前提principle of compositionality 语意合成性原理privative 二元对立的probabilistic parser 概率句法剖析程序problem solving 解决问题program 程序programming language 程序设计语言 [程序设计语言] proofreading system 校对系统proper name 专有名词prosody 节律prototype 原型pseudo-cleft sentence 准分裂句psycholinguistics 心理语言学punctuation 标点符号pushdown automata 下推自动机pushdown transducer 下推转换器qualification 后置修饰quantification 量化quantifier 范域词quantitative linguistics 计量语言学question answering system 问答系统queue 队列radical 字根 [词干;词根;部首;偏旁]radix of tuple 元组数基random access 随机存取rationalism 理性论rationalist (position) 理性论立场 [唯理论观点]reading laboratory 阅读实验室real time 实时real time control 实时控制 [实时控制]recursive transition network 递归转移网络reduplication 重叠词 [重复]reference 指涉referent 指称对象referential indices 指针referring expression 指涉词 [指示短语]register 缓存器[寄存器]{信息科学}/调高{语音学}/语言的场合层级{社会语言学}regular language 正规语言 [正则语言]relational database 关系型数据库 [关系数据库]relative clause 关系子句relaxation method 松弛法relevance 相关性restricted logic grammar 受限逻辑语法resumptive pronouns 复指代词retroactive inhibition 逆抑制rewriting rule 重写规则rheme 述位rhetorical structure 修辞结构rhetorics 修辞学robust 强健性robust processing 强健性处理robustness 强健性schema 基朴school grammar 教学语法scope 范域 [作用域;范围]script 脚本search mechanism 检索机制search space 检索空间searching route 检索路径 [搜索路径]second order predicate 二阶述词segmentation 分词segmentation marker 分段标志selectional restriction 选择限制semantic field 语意场semantic frame 语意架构semantic network 语意网络semantic representation 语意表征 [语义表示] semantic representation language 语意表征语言semantic restriction 语意限制semantic structure 语意结构semantics 语意学sememe 意素semiotics 符号学sender 发送者sensorimotor stage 感觉运动期sensory information 感官讯息 [感觉信息]sentence 句子sentence generator 句子产生器 [句子生成程序]sentence pattern 句型separation of homonyms 同音词区分sequence 序列serial order learning 顺序学习serial verb construction 连动结构set oriented semantic network 集合导向型语意网络 [面向集合型语意网络]sgml (standard generalized markup language) 结构化通用标记语言shift-reduce parsing 替换简化式剖析short term memory 短程记忆sign 信号signal processing technology 信号处理技术simple word 单纯词situation 情境situation semantics 情境语意学situational type 情境类型social context 社会环境sociolinguistics 社会语言学software engineering 软件工程 [软件工程]sort 排序speaker-independent speech recognition 非特定语者语音识别spectrum 频谱speech 口语speech act assignment 言语行为指定speech continuum 言语连续体speech disorder 语言失序 [言语缺失]speech recognition 语音辨识speech retrieval 语音检索speech situation 言谈情境 [言语情境]speech synthesis 语音合成speech translation system 语音翻译系统speech understanding system 语音理解系统spreading activation model 扩散激发模型standard deviation 标准差standard generalized markup language 标准通用标示语言start-bound complement 接头词state of affairs algebra 事态代数state transition diagram 状态转移图statement kernel 句核static attribute list 静态属性表statistical analysis 统计分析statistical linguistics 统计语言学statistical significance 统计意义stem 词干stimulus-response theory 刺激反应理论stochastic approach to parsing 概率式句法剖析 [句法剖析的随机方法]stop 爆破音stratificational grammar 阶层语法 [层级语法]string 字符串[串；字符串]string manipulation language 字符串操作语言string matching 字符串匹配 [字符串]structural ambiguity 结构歧义structural linguistics 结构语言学structural relation 结构关系structural transfer 结构转换structuralism 结构主义structure 结构structure sharing representation 结构共享表征subcategorization 次类划分 [下位范畴化] subjunctive 假设的sublanguage 子语言subordinate 从属关系subordinate clause 从属子句 [从句;子句] subordination 从属substitution rule 代换规则 [置换规则] substrate 底层语言suffix 后缀superordinate 上位的superstratum 上层语言suppletion 异型[不规则词型变化] suprasegmental 超音段的syllabification 音节划分syllable 音节syllable structure constraint 音节结构限制symbolization and verbalization 符号化与字句化synchronic 同步的synonym 同义词syntactic category 句法类别syntactic constituent 句法成分syntactic rule 语法规律 [句法规则]syntactic semantics 句法语意学syntagm 句段syntagmatic 组合关系 [结构段的;组合的] syntax 句法systemic grammar 系统语法tag 标记target language 目标语言 [目标语言]task sharing 课题分享 [任务共享] tautology 套套逻辑 [恒真式;重言式;同义反复] taxonomical hierarchy 分类阶层 [分类层次] telescopic compound 套装合并template 模板temporal inference 循序推理 [时序推理] temporal logic 时间逻辑 [时序逻辑] temporal marker 时貌标记tense 时态terminology 术语text 文本text analyzing 文本分析text coherence 文本一致性text generation 文本生成 [篇章生成]text linguistics 文本语言学text planning 文本规划text proofreading 文本校对text retrieval 文本检索text structure 文本结构 [篇章结构]text summarization 文本自动摘要 [篇章摘要] text understanding 文本理解text-to-speech 文本转语音thematic role 题旨角色thematic structure 题旨结构theorem 定理thesaurus 同义词辞典theta role 题旨角色theta-grid 题旨网格token 实类 [标记项]tone 音调tone language 音调语言tone sandhi 连调变换top-down 由上而下 [自顶向下]topic 主题topicalization 主题化 [话题化]trace 痕迹trace theory 痕迹理论training 训练transaction 异动 [处理单位]transcription 转写 [抄写;速记翻译]transducer 转换器transfer 转移transfer approach 转换方法transfer framework 转换框架transformation 变形 [转换]transformational grammar 变形语法 [转换语法] transitional state term set 转移状态项集合transitivity 及物性translation 翻译translation equivalence 翻译等值性translation memory 翻译记忆transparency 透明性tree 树状结构 [树]tree adjoining grammar 树形加接语法 [树连接语法] treebank 树图数据库[语法关系树库]trigram 三连词t-score t-数turing machine 杜林机 [图灵机]turing test 杜林测试 [图灵试验]type 类型type/token node 标记类型/实类节点type-feature structure 类型特征结构typology 类型学ultimate constituent 终端成分unbounded dependency 无界限依存underlying form 基底型式underlying structure 基底结构unification 连并 [合一]unification-based grammar 连并为本的语法 [基于合一的语法] universal grammar 普遍性语法universal instantiation 普遍例式universal quantifier 全称范域词unknown word 未知词 [未定义词]unrestricted grammar 非限制型语法usage flag 使用旗标user interface 使用者界面 [用户界面]valence grammar 结合价语法valence theory 结合价理论valency 结合价variance 变异数 [方差]verb 动词verb phrase 动词组 [动词短语]verb resultative compound 动补复合词verbal association 词语联想verbal phrase 动词组verbal production 言语生成vernacular 本地话v-o construction (verb-object) 动宾结构vocabulary 字汇vocabulary entry 词条vocal track 声道vocative 呼格voice recognition 声音辨识 [语音识别]vowel 元音vowel harmony 元音和谐 [元音和谐]waveform 波形weak verb 弱化动词whorfian hypothesis whorfian 假说word 词word frequency 词频word frequency distribution 词频分布word order 词序word segmentation 分词word segmentation standard for chinese 中文分词规范word segmentation unit 分词单位 [切词单位]word set 词集working memory 工作记忆 [工作存储区]world knowledge 世界知识writing system 书写系统x-bar theory x标杠理论 ["x"阶理论]zipf's law 利夫规律 [齐普夫定律]。
英语过渡词的功能
IntroductionTransition words, often referred to as linking or connecting words, are linguistic devices that serve as conduits between ideas, sentences, and paragraphs. They facilitate the smooth flow of thoughts, enhance clarity, and strengthen the logical coherence of written or spoken discourse. These seemingly inconspicuous words play an indispensable role in shaping the structure, organization, and overall effectiveness of communication in the English language. This essay provides a comprehensive, multi-faceted analysis of the functions of transition words, delving into their significance from various perspectives and underscoring their paramount importance in achieving high-quality, coherent writing.1. Enhancing Logical CoherenceOne of the primary functions of transition words is to establish clear relationships between ideas, ensuring that readers can effortlessly follow the progression of thought. By signaling cause and effect (e.g., "therefore," "consequently"), contrast (e.g., "however," "on the other hand"), similarity (e.g., "likewise," "similarly"), or sequence (e.g., "firstly," "next"), transition words create a logical bridge between separate sentences or paragraphs. They help readers anticipate the direction of the argument, enabling them to comprehend complex information more efficiently. Furthermore, transitions clarify the hierarchy of ideas, indicating whether a new point is being introduced, an example is being provided, or a conclusion is being drawn. This logical coherence not only enhances readability but also fortifies the persuasiveness and credibility of the writer's argument.2. Facilitating Paragraph Unity and CohesionIn the realm of paragraph construction, transition words serve as vital tools for maintaining unity and cohesion. They bind together the sentences within a paragraph, ensuring that each sentence contributes to the development of the central topic or main idea. Transitions such as "in addition," "furthermore," and "moreover" introduce supplementary information, while "for instance,""specifically," and "to illustrate" introduce examples that support the main point. By seamlessly integrating these elements, transition words prevent the paragraph from becoming a mere collection of disparate statements, fostering instead a cohesive, unified whole. This unity, in turn, enables readers to grasp the essence of the paragraph without getting lost in a sea of disconnected details.3. Enhancing Textual Flow and RhythmTransition words contribute significantly to the aesthetic dimension of writing, imbuing it with a natural, harmonious flow. They act as syntactic signposts, guiding readers through the text and mitigating potential disorientation caused by abrupt shifts in focus or tone. For instance, temporal transitions like "meanwhile," "subsequently," and "eventually" help narrate events in a chronological order, while spatial transitions like "adjacent to," "beyond," and "surrounding" assist in describing spatial relationships. Additionally, transition words can soften the impact of contrasting ideas or opposing viewpoints, employing phrases like "although," "despite," or "in spite of" to introduce counterarguments or qualifications smoothly. This seamless progression of ideas not only enhances the reader's experience but also bolsters the rhetorical power of the text.4. Strengthening Argumentation and PersuasionIn persuasive or argumentative writing, transition words play a critical role in structuring and reinforcing the writer's position. They help articulate the logical connections between premises and conclusions, making the reasoning process transparent to the reader. Transitions like "since," "because," "hence," and "thus" establish cause-and-effect relationships, while "in conclusion," "therefore," and "ultimately" signal the drawing of final inferences. Moreover, contrastive transitions like "although," "while," and "yet" can effectively highlight the weaknesses in opposing arguments or alternative viewpoints, bolstering the writer's stance. By using transition words judiciously, writers can construct compelling, well-supported arguments that are more likely topersuade their audience.5. Improving Clarity and PrecisionTransition words contribute to the precision and clarity of language by specifying the nature of the relationship between ideas. They eliminate ambiguity, ensuring that readers understand exactly how different pieces of information relate to one another. For example, using "nevertheless" or "nonetheless" makes it clear that a contrasting idea is being presented despite the preceding statement, whereas "in contrast" or "on the contrary" signals a direct opposition. Similarly, transitions like "in other words," "that is," or "namely" serve to clarify or rephrase complex concepts, making them more accessible to the reader. By enhancing precision and clarity, transition words help writers convey their intended meaning accurately, reducing the likelihood of misinterpretation or confusion.6. Enabling Effective Summarization and Conclusion FormationTransition words are instrumental in summarizing key points and drawing effective conclusions. Phrases like "in summary," "to sum up," or "overall" clearly indicate the beginning of a summary, while "in conclusion," "finally," or "thus" signal the presentation of the writer's final thoughts or recommendations. These transitions help readers recognize when the writer is synthesizing information, reiterating crucial points, or formulating overarching insights. In doing so, they facilitate the retention of information and reinforce the message's impact, leaving a lasting impression on the reader.7. Promoting Academic Writing StandardsIn academic writing, where rigorous organization, clarity, and precision are paramount, transition words are indispensable. They help writers adhere to established conventions, such as the use of topic sentences, supporting evidence, and logical transitions between paragraphs. Transitions like "in light of," "given," and "considering" introduce evidence or background information, while "according to," "as stated by," or "as demonstrated in" cite sources appropriately. Moreover, transition words facilitate the integration ofopposing views or counterarguments, demonstrating a writer's awareness of diverse perspectives and enhancing the intellectual rigor of their work. By consistently employing transition words, academic writers demonstrate their mastery of disciplinary discourse, earning credibility and enhancing the overall quality of their research.ConclusionTransition words, though seemingly modest in stature, wield immense power in shaping the structure, clarity, and effectiveness of communication in the English language. Their multifaceted functions – enhancing logical coherence, facilitating paragraph unity and cohesion, improving textual flow and rhythm, strengthening argumentation and persuasion, promoting clarity and precision, enabling effective summarization and conclusion formation, and upholding academic writing standards – attest to their indispensable role in producing high-quality, coherent writing. As such, a conscious, strategic use of transition words should be an integral part of any writer's toolkit, serving as a cornerstone for clear, compelling, and impactful communication across various genres and contexts.。
最新理论试题及答案英语
最新理论试题及答案英语一、选择题（每题1分，共10分）1. The word "phenomenon" is most closely related to which of the following concepts?A. EventB. FactC. TheoryD. Hypothesis答案：C2. In the context of scientific research, what does the term "hypothesis" refer to?A. A proven factB. A testable statementC. A final conclusionD. An unverifiable assumption答案：B3. Which of the following is NOT a characteristic of scientific theories?A. They are based on empirical evidence.B. They are subject to change.C. They are always universally applicable.D. They are supported by a body of evidence.答案：C4. The scientific method typically involves which of the following steps?A. Observation, hypothesis, experimentation, conclusionB. Hypothesis, observation, conclusion, experimentationC. Experimentation, hypothesis, observation, conclusionD. Conclusion, hypothesis, observation, experimentation答案：A5. What is the role of experimentation in the scientific process?A. To confirm a hypothesisB. To disprove a hypothesisC. To provide evidence for or against a hypothesisD. To replace the need for a hypothesis答案：C6. The term "paradigm shift" in the philosophy of science refers to:A. A minor change in scientific theoryB. A significant change in the dominant scientific viewC. The process of scientific discoveryD. The end of scientific inquiry答案：B7. Which of the following is an example of inductive reasoning?A. Observing a pattern and making a general ruleB. Drawing a specific conclusion from a general ruleC. Making a prediction based on a hypothesisD. Testing a hypothesis through experimentation答案：A8. Deductive reasoning is characterized by:A. Starting with a specific observation and drawing a general conclusionB. Starting with a general rule and applying it to a specific caseC. Making assumptions without evidenceD. Relying on intuition rather than logic答案：B9. In scientific research, what is the purpose of a control group?A. To provide a baseline for comparisonB. To test an alternative hypothesisC. To increase the number of participantsD. To confirm the results of previous studies答案：A10. The principle of falsifiability, introduced by Karl Popper, suggests that:A. Scientific theories must be proven trueB. Scientific theories must be able to withstand attempts at being disprovenC. Scientific theories are never wrongD. Scientific theories are always based on personal beliefs答案：B二、填空题（每题1分，共5分）1. The scientific method is a systematic approach to__________ knowledge through observation, experimentation, and __________.答案：gaining; logical reasoning2. A scientific law is a statement that describes a__________ pattern observed in nature, while a scientific theory explains the __________ behind these patterns.答案：recurring; underlying principles3. The process of peer review in scientific publishing is important because it helps to ensure the __________ and__________ of research findings.答案：validity; reliability4. In the context of scientific inquiry, an __________ is a tentative explanation for an aspect of the natural world that is based on a limited range of __________.答案：hypothesis; observations5. The term "empirical" refers to knowledge that is based on __________ and observation, rather than on theory or__________.答案：experimentation; speculation三、简答题（每题5分，共10分）1. Explain the difference between a scientific theory and a scientific law.答案：A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experimentation. It is a broad framework that can encompass multiple laws and observations. A scientific law, on the other hand, is a concise verbal or mathematical statement that describes a general pattern observed in nature. Laws summarize specific phenomena, while theories explain the broader principles behind those phenomena.2. What is the significance of the falsifiability criterionin the philosophy of science?答案：The falsifiability criterion, proposed byphilosopher of science Karl Popper, is significant because it provides a way to distinguish between scientific and non-scientific theories. For a theory to be considered scientific, it must be testable and potentially refutable by empirical evidence. This criterion ensures that scientific theories are open。
英国历史文化概况UNIT 4 Laws and Rules
TEXT A Notes
• 7. The House of Lords (commonly referred to as "the Lords", officially referred to as the "Lords Spiritual and Temporal" in Acts of Parliament, and as the "House of Peers" for some ceremonial purposes) is the upper house of the Parliament of the United Kingdom, the United Kingdom's national legislature. Parliament comprises the Sovereign, the House of Commons (which is the lower house of Parliament and referred to as "the Commons"), and the Lords. The House of Lords, like the House of Commons, assembles in the Palace of Westminster.
• 2. The Royal Prerogative is a body of customary authority, privilege, and immunity, recognised in the United Kingdom as the sole prerogative of the Sovereign. Many of the executive powers of British government, vested in a monarch, have been bestowed under the mandate of the Royal Prerogative.
电子信息英文
电子信息英文The following referenced documents are indispensable for the application of this standard. For dated references,only the edition cited applies. For undated references, the latest edition of the referenced document(including any amendments or corrigenda) applies.2.1 IEEE documentsIEEE Std 802, IEEE Standards for Local and Metropolitan Area Networks: Overview and Architecture.IEEE Std 802.15.2™, IEEE Recommended Practice for Telecommunications and Information exchange between systems—Local and metropolitan area networks—Specific Requirements—Part 15.2: Coexistence of Wireless Personal Area Networks with Other Wireless Devices Operating in Unlicensed Frequency Band.2.2 ISO documentsISO/IEC 3309, Information technology — Telecommunications and information exchange between systems—High-level data link control (HDLC) procedures — Frame structure.ISO/IEC 7498-1, Information technology —Open Systems Interconnection — Basic Reference Model: The Basic Model.ISO/IEC 8802-2, Information technology —Telecommunicationsand information exchange between systems—Local and metropolitan area networks —Specific requirements —Part 2: Logical link control.ISO/IEC 10039, Information technology —Open Systems Interconnection — Local Area Networks —Medium Access Control (MAC) service definition.ISO/IEC 15802-1, Information technology —Telecommunications and information exchange between systems—Local and metropolitan area networks —Common specifications —Part 1: Medium Access Control (MAC) service definition.2.3 ITU documentsITU-T Recommendation G.711, Pulse code modulation (PCM) of voice frequencies.ITU-T Recommendation O.150, Digital test patterns for performance measurements on digital transmission equipment. ITU-T Recommendation O.153, Basic parameters for the measurement of error performance at bit rates below the primary rate.ITU-T Recommendation X.200, Information technology—Open systems interconnection—Basic reference model: The basic model.2.4 Other documentsIETF RFC 1363, A Proposed Flow Specification.IETF RFC 1661, The Point-to-Point Protocol (PPP).IrDA Object Exchange Protocol (IrOBEX), Version 1.23. DefinitionsFor the purposes of this standard, the following terms and definitions apply. The Authoritative Dictionary of IEEE Standards Terms, Seventh Edition [B7], should be referenced for terms not defined in this clause.3.1 active slave broadcast (ASB): The logical transport that is used to transport Logical Link Control and Adaptation Protocol (L2CAP) user traffic to all active devices in the piconet.3.2 ad hoc network: A network typically created in a spontaneous manner. An ad hoc network requires no formal infrastructure and is limited in temporal and spatial extent.3.3 authenticated device: A device whose identity has been verified during the lifetime of the current link,based on the authentication procedure.3.4 authentication: A generic procedure based on link management profile authentication that determines whether a link key exists or, on Link Manager Protocol (LMP) pairing, whether no link key exists.3.5 authorization: A procedure where a user of a device grants a specific (remote) device access to a specific service. Authorizationimplies that the identity of the remote device can be verified through authentication.3.6 authorize: The act of granting a specific device access to a specific service. It may be based upon user confirmation or given the existence of a trusted relationship.3.7 baseband (BB): The part of the system that specifies or implements the medium access control (MAC) layer and physical layer (PHY) procedures to support the exchange of real-time voice, data information streams, and ad hoc networking between devices.3.8 beacon train: A pattern of reserved slots within a basic or adapted piconet physical channel. Transmissions starting in these slots are used to resynchronize parked devices.3.9 Bluetooth device address (BD_ADDR): The address used to identify a device conforming to this standard.3.10 Bluetooth wireless technology: The general term used to describe the technolgy orginally developed by the Bluetooth Special Interest Group (SIG). It defines a wireless communication link, operating in the unlicensed industrial, scientific, and medical (ISM) band at 2.4 GHz using a frequency hopping transceiver.The link protocol is based on time slots.3.11 bond: A relation between two devices defined by creating, exchanging, and storing a common link key The bond is createdthrough the bonding or Link Manager Protocol (LMP) pairing procedures.3.12 channel: Either a physical channel or an Logical Link Control and Adaptation Protocol (L2CAP) channel,depending on the context.3.13 connect (to service): The establishment of a connection to a service. If not already done, this also includes establishment of a physical link, logical transport, logical link, and Logical Link Control and Adaptation Protocol (L2CAP) channel.3.14 connectable device: A device in range that periodically listens on its page scan physical channel and will respond to a page on that channel.3.15 connected devices: Two devices in the same piconet and witha physical link between them.3.16 connecting: A phase in the communication between devices when a connection between them is being established. (Connecting phase follows after the link establishment phase is completed.)3.17 connection: A connection between two peer applications or higher layer protocols mapped onto a Logical Link Control and Adaptation Protocol (L2CAP) channel.3.18 connection establishment: A procedure for creating aconnection mapped onto a channel.3.19 controller: A subsystem containing the physical layer (PHY), baseband (BB), resource controller, link manager (LM), device manager, and a host controller interface (HCI) conforming to this standard.3.20 coverage area: The area where two devices can exchange messages with acceptable quality and performance.3.21 creation of a secure connection: A procedure of establishing a connection, including authentication and encryption.3.22 creation of a trusted relationship: A procedure where the remote device is marked as a trusted device.This includes storing a common link key for future authentication and pairing (if the link key is not available).3.23 device: A device that is capable of short-range wireless communications using this standard.3.24 device address: A 48-bit address used to identify each device.3.25 device discovery: A procedure for retrieving the device address, clock, class-of-device field, and used page scan mode from discoverable devices.3.26 discoverable device: A device in range that periodically listens on an inquiry scan physical channel and will respond to an inquiry on that channel. Discoverable devices are normally alsoconnectable.3.27 estimated clock (CLKE): Estimate of another device’s clock. CLKE may be a slave’s estimate of a master’s clock, a paging devices’s estimate of the paged device’s clock, or other such use.3.28 host: A computing device, peripheral, cellular telephone, access point to public switched telephone network (PSTN) or local area network (LAN), etc. A host attached to a controller may communicate with other hosts attached to their controllers as well.3.29 host controller interface (HCI): A command interface to the baseband (BB) controller and link manager (LM) that provides access to hardware status and control registers and provides a uniform method of accessing the BB capabilities.3.30 idle: Description of a device, as seen from a remote device, when no link is established between the devices.3.31 inquiring device: A device that is carrying out the inquiry procedure.3.32 inquiry: A procedure where a device transmits inquiry messages and listens for responses in order to discover the other devices that are within the coverage area.3.33 inquiry scan: A procedure where a device listens for inquiry messages received on its inquiry scan physical channel.3.34 isochronous data: Information in a stream where eachinformation entity in the stream is bound by a time relationship to previous and successive entities.3.35 known device: A device for which at least the Bluetooth device address (BD_ADDR) is stored.3.36 link: Shorthand for a logical link.3.37 link establishment: A procedure for establishing the default ACL link and hierarchy of links and channels between devices.3.38 link key: A secret key that is known by two devices and is used in order to authenticate each device to the other.3.39 LMP authentication: A procedure on the Link Manager Protocol (LMP) level for verifying the identity of a remote device. The procedure is based on a challenge-response mechanism using a random number, a secret key, and the Bluetooth device address (BD_ADDR) of the noninitiating device. The secret key used can bea previously exchanged link key.3.40 LMP pairing: A procedure that authenticates two devices, based on a personal identification number (PIN), and subsequently creates a common link key that can be used as a basis for a trusted relationship or a (single) secure connection. The procedure consists of the following steps: creation of an initialization key (based on a random number and a PIN), creation and exchange of a common link key, and Link Manager Protocol (LMP)authentication based on the common link key.3.41 logical channel: Identical to a Logical Link Control and Adaptation Protocol (L2CAP) channel, but deprecated due to inconsistent usage in IEEE Std802.15.1-2002.3.42 logical link: The lowest architectural level used to offer independent data transport services to clients of the system.3.43 logical transport: Used to represent commonality between different logical links due to shared acknowledgement protocol and link identifiers.3.44 L2CAP channel: A logical connection on the Logical Link Control and Adaptation Protocol (L2CAP) level between two devices serving a single application or higher layer protocol.3.45 L2CAP channel establishment: A procedure for establishing a logical connection on the Logical Link Control and Adaptation Protocol (L2CAP) level.3.46 master clock (CLK): Native clock of the piconet’s master.3.47 mode: A set of directives that defines how a device will respond to certain events.3.48 name discovery: A procedure for retrieving the user-friendly name (the device name) of a connectable device.3.49 native clock (CLKN): A 28-bit clock internal to a controller subsystem that ticks every 312.5μs. The value of this clockdefines the slot numbering and timing in the various physical channels.3.50 packet: Format of aggregated bits that are transmitted on a physical channel.3.51 page: The initial phase of the connection procedure where a device transmits a train of page messages until a response is received from the target device or a timeout occurs.3.52 page scan: A procedure where a device listens for page messages received on its page scan physical channel.3.53 paging device: A device that is carrying out the page procedure.3.54 paired device: A device with which a link key has been exchanged (either before connection establishment was requested or during connecting phase).3.55 parked device: A device operating in a basic mode piconet that is synchronized to the master, but has given up its default ACL logical transport.3.56 parked slave broadcast (PSB): The logical transport that is used for communications from the master to parked slave devices. These communications may also be received by active devices. 3.57 participant in multiple piconets: A device that is concurrently a member of more than one piconet. It achieves this status using timedivision multiplexing (TDM) to interleave its activity on each piconet physical channel.3.58 personal identification number (PIN): A user-friendly number that can be used to authenticate connections to a device before pairing has taken place.3.59 physical channel: A channel characterized by synchronized occupancy of a sequence of radio frequency (RF) carriers by one or more devices. A number of physical channel types exist with characteristics defined for their different purposes.3.60 physical link: A connection on the baseband (BB) level between two devices established using paging.3.61 piconet: A collection of devices occupying a shared physical channel where one of the devices is the piconet master and the remaining devices are connected to it.3.62 piconet physical channel: A channel that is divided into time slots in which each slot is related to a radio frequency (RF) hop frequency. Consecutive hops normally correspond to different RF hop frequencies and occur at a standard hop rate of 1600 hop/s. These consecutive hops follow a pseudo-random hopping sequence, hopping through a 79-RF channel set, or optionally fewer channels when adaptive frequency hopping (AFH) is in used.3.63 piconet master: The device in a piconet whose clock anddevice address are used to define the piconet physical channel characteristics.3.64 piconet slave: Any device in a piconet that is not the piconet master, but is connected to the piconet master, and that controls piconet timing and access by its transmissions to slaves.3.65 prepaired device: A device with which a link key was exchanged and stored before link establishment.3.66 scatternet: Two or more piconets that include one or more devices participating in more than one piconet.3.67 service discovery (SD): Procedures for querying and browsing for services offered by or through another device.3.68 service layer protocol: A protocol that uses a Logical Link Control and Adaptation Protocol (L2CAP) channel for transporting protocol data units (PDUs).3.69 silent device: A device appears as silent to a remote device if it does not respond to inquiries made by the remote device.3.70 trusted device: A paired device that is explicitly marked as trusted.3.71 unknown device: A device for which no information (e.g., device address, link key) is stored.3.72 unpaired device: A device for which there was no exchanged link key available before connection establishment was requested.6. ArchitectureThis standard is a formalization of Bluetooth wireless technology, a short-range communications system intended to replace the cable(s) connecting portable and/or fixed electronic devices. Key features are robustness,low power, and low cost. Many features of the core specification are optional, allowing product differentiation.The term core system is used in this clause to denote the combination of a radio frequency (RF) transceiver, BB, and protocol stack. The system offers services that enable the connection of devices and the exchange of a variety of classes of data between these devices.This clause of this standard provides an overview of the system architecture, communication topologies, and data transport features. This clause is informative.6.1 General descriptionThe RF (PHY) operates in the unlicensed ISM band at 2.4 GHz.. The system employs a frequency hop transceiver to combat interference and fading and provides many frequency hopping spread spectrum (FHSS) carriers. RF operation uses a shaped binary frequency modulation to minimize transceiver complexity. The symbol rate is 1 Msymbol/s supporting the bit rate of 1 Mb/s.During typical operation, a physical radio channel is shared by a group of devices that are synchronized to a common clock and frequency hopping pattern. One device provides the synchronization reference and is known as the master. All other devices are known as slaves. A group of devices synchronized in this fashion form a piconet. This is the fundamental form of communication in the technology.Devices in a piconet use a specific frequency hopping pattern, which is algorithmically determined by fields in the device address and the clock of the master. The basic hopping pattern is a pseudo-random ordering of the 79 frequencies in the ISM band. The hopping pattern may be adapted to exclude a portion of the frequencies that are used by interfering devices. The adaptive hopping technique improves coexistence with static (non hopping) ISM systems when these are collocated and implements some of the recommendations of IEEE Std 802.15.2-2003.The physical channel is subdivided into time units known as slots. Data are transmitted between devices in packets, which are positioned in these slots. When circumstances permit, a number of consecutive slots may be allocated to a single packet. Frequency hopping takes place between the transmission or the reception of packets. This standard provides the effect of full duplextransmission through the use of a time-division duplex (TDD) scheme.Above the physical channel, there is a layering of links and channels and associated control protocols. The hierarchy of channels and links from the physical channel upwards is physical channel, physical link, logical transport, logical link, and L2CAP channel. These are discussed in more detail in 6.4.4 through 6.5, but are introduced here to aid the understanding of the remainder of this clause.Within a physical channel, a physical link is formed between any two devices that transmit packets in either direction between them. In a piconet physical channel, there are restrictions on which devices may form a physical link. There is a physical link between each slave and the master. Physical links are not formed directly between the slaves in a piconet.The physical link is used as a transport for one or more logical links that support unicast synchronous, asynchronous and isochronous traffic, and broadcast traffic. Traffic on logical links is multiplexed onto the physical link by occupying slots assigned by a scheduling function in the resource manager.A control protocol for the BB layer and PHY is carried over logical links in addition to user data. This is the LMP. Devices thatare active in a piconet have a default asynchronous connection-oriented (ACL) logical transport that is used to transport the LMP signalling. For historical reasons, this is referred to as the ACL logical transport. The default ACL logical transport is the one that is created whenever a device joins a piconet. Additional logical transports may be created to transport synchronous data streams when this is required.The LM function uses LMP to control the operation of devices in the piconet and provide services to manage the lower architectural levels (i.e., PHY and BB). The LMP is carried only on the default ACL logical transport and the default broadcast logical transport.Above the BB, L2CAP provides a channel-based abstraction to applications and services. It carries out segmentation and reassembly (SAR) of application data and multiplexing and demultiplexing of multiple channels over a shared logical link. L2CAP has a protocol control channel that is carried over the default ACL logical transport. Application data submitted to the L2CAP may be carried on any logical link that supports the L2CAP.6.2 Core system architectureThe core system covers the four lowest segments and associated protocols defined by this standard, and the overallprofile requirements are specified in the generic access profile (GAP) (see Annex B). A complete application generally requires a number of additional service and higher layer protocols that are defined in the Bluetooth specification and are not described in this standard. The core system architecture is shown in Figure 1.Core system architecture shows the four lowest layers, each with its associated communication protocol. The lowest three layers are sometimes grouped into a subsystem (known as the controller). This is a common implementation involving a standard physical communications interface (i.e., the host controller interface or HCI) and remainder of the system. This includes the L2CAP, service, and higher layers (known as the host). Although this interface is optional, the architecture is designed to allow for its existence and characteristics. This standard enables interoperability between independent systems by defining the protocol messages exchanged between equivalent layers and also interoperability between independent subsystems by defining a common interface between controllers and hosts.A number of functional blocks are shown in Figure 1 and the path of services and data between these. The functional blocks shown in the diagram are informative; in general, this standard does not define the details of implementations except where this isrequired for interoperability. Thus the functional blocks in Figure 1 are shown in order to aid description of the system behavior. An implementation may be different from the system shown in Figure 1.Standard interactions are defined for all inter-device operation, where devices exchange protocol signalling according to this standard. The core system protocols are the Radio Frequency (RF) Protocol, Link Control Protocol (LCP), LMP, and L2CAP, all of which are fully defined in subsequent parts of this standard.The core system offers services through a number of service access points (SAPs) that are shown in Figure 1 as ellipses. These services consist of the basic primitives that control the core system. The services can be split into three types:— Device control services that modify the behavior and modes of a device— Transport control services that create, modify, and release traffic bearers (channels and links)— Data services that are used to submit data for transmission over traffic bearersIt is common to consider the first two as belonging to the C-plane and the last as belonging to the U-plane.Figure 1—Core system architectureA service interface to the controller subsystem is defined so that the controller may be considered a standard part. In this configuration, the controller operates the lowest three layers, and L2CAP is contained with the rest of the application in a host system. This standard interface is called the host controller interface (HCI), and its SAPs are represented by the ellipses on the upper edge of the controller subsystem in Figure 1. Implementation of this standard service interface is optional.As the architecture is defined with the possibility of separate host and controller communicating through an HCI, a number of general assumptions are made. The controller is assumed to have limited data buffering capabilities in comparison with the host. Therefore, L2CAP is expected to carry out some simple resource management when submitting L2CAP protocol data units (PDUs) to the controller for transport to a peer device. This includessegmentation of L2CAP service data units (SDUs) into more manageable PDUs and then the fragmentation of PDUs into start and continuation packets of a size suitable for the controller buffers, and management of the use of controller buffers to ensure availability for channels with quality of service (QoS) commitments.The BB protocol provides the basic ARQ Protocol. The L2CAP can optionally provide a further error detection and retransmission to the L2CAP PDUs. This feature is recommended for applications with requirements for a low probability of undetected errors in the user data. A further optional feature of L2CAP is a window-based flow control that can be used to manage buffer allocation in the receiving device. Both of these optional features augment the QoS performance in certain scenarios.6.3 Core architectural blocksThis subclause describes the function and responsibility of each of the blocks shown in Figure 1, which describes a possible implementation architecture. An implementation is not required to follow the architecture described in this clause.。
Abstract
Fibring Labelled Deduction SystemsJo˜a o Rasga,Am´ılcar Sernadas,Cristina SernadasCMA,Departamento de Matem´a tica,ISTAv.Rovisco Pais1049-001Lisbon,Portugalhttp://www.cs.math.ist.utl.pt/s84.www/cs/{jfr,acs,css}.html{jfr,acs,css}@math.ist.utl.ptLuca Vigan`oInstitut f¨u r InformatikAlbert-Ludwigs-Universit¨a t FreiburgGeorges-K¨o hler-Allee52D-79110Freiburg,Germanyrmatik.uni-freiburg.de/~lucaluca@informatik.uni-freiburg.deAbstractWe give a categorial characterization of how labelled deduction systems for logics with a propositional basis behave under unconstrainedfibring and underfibring that is constrained by symbol sharing.At the semantic level,we introduce a general semantics for our systems and then give a categorial characterization offibring of models.Based on this,we establish the conditions under which our systems are sound and complete with respect to the general semantics for the corresponding logics,and establish requirements on logics and systems so that completeness is preserved by both forms offibring.Keywords:Fibring of Logics,Labelled Deduction Systems,Natural Deduction,Gen-eral Semantics,Category Theory.1IntroductionContext The problem of combining logics has attracted much attention lately.Be-sides leading to interesting applications whenever it is necessary to work with dif-ferent logics at the same time,combining logics is also interesting on purely the-oretical grounds[7],and among the different techniques for combining logics,fib-ring[15,17,18,25,26,29]deserves close study.Thefibring of two logics is obtained by combining their languages,deduction systems and semantics.The language of thefibring is obtained by allowing the use of the language constructors(atomic symbols and connectives)from the logics that we want to combine.So,for example,whenfibring a temporal logic and a deontic logic,“mixed”formulae,like((Gα)⇒(O(Fβ))),appear in the resulting logic.In manycases one wants to share some of the symbols,and we then speak offibring constrainedby symbol sharing.For example,the formula above illustrates the constrained form offibring imposed by sharing the common propositional part of a temporal and a deonticlogic.Alternatively,we may consider unconstrainedfibring,where no symbols of thetwo given logics are shared.The deduction system of thefibring is obtained by the free use of the inferencerules from both given logics,provided that these logics are endowed with deductionsystems of the same kind(e.g.both logics with Hilbert systems or both with naturaldeduction systems).Moreover,this approach is of practical interest only if the twogiven deduction systems are schematic,in the sense that their inference rules are“open”for application to formulae with“foreign”symbols.For instance,when insome Hilbert system modus ponens is defined by the rule MP,{(ξ1⇒ξ2),ξ1} ξ2, one may implicitly assume that the instantiation of the metavariablesξ1andξ2byany formulae,possibly with symbols from both logics,is allowed when applying MPin thefibring.The semantics of thefibring is complicated and,similar to deduction systems,it is better to consider the case where both logics have semantics of the same kind(i.e.with similar models).A possible,quite general,model for many logics with apropositional basis is provided by a triple U,B,ν where U is a set(of points,worlds,states,whatever),B⊆℘U,andν(c):B n→B for each language constructor c of arity n≥0.Given two logics L and L with such a semantics,the semantics of their fibring is a class of models of the form U,B,ν ,such that at each point u∈U it is possible to extract a model from L and one from L .If symbols are shared,the two extracted models should agree on them.This paper follows a program started by[25],where a categorial characterization offibring of logics with a propositional basis is presented,continued in[26]with the studyoffibring of logics with terms and binding operators,and in[29]where preservationof(strong)completeness byfibring is obtained for logics with a propositional basis.All these works consider Hilbert-style deduction systems.Here,we concentrate ourattention onfibring of logics endowed with labelled deduction systems.To illustrate why considering these systems is important,observe that Hilbert-stylesystems,although uniform,are difficult to use in practice,especially in comparisonwith the more“natural”Gentzen-style systems such as natural deduction,sequentand tableaux systems.Unfortunately,devising Gentzen-style systems for modal,rel-evance and other non-classical logics often requires considerable ingenuity,as well astrading uniformity for simplicity and usability.A solution to this problem is to em-ploy labelling techniques,which provide a general framework for presenting differentlogics in a uniform way in terms of Gentzen-style deduction systems.The intuitionbehind these techniques is that labelling(sometimes also called prefixing,annotatingor subscripting)allows one to explicitly encode additional information,of a semanticor proof-theoretical nature,that is otherwise implicit in the logic one wants to cap-ture.So,for instance,instead of considering a modal formulaϕ,we can consider thelabelled formula w:ϕ,which intuitively means thatϕholds at the point denoted byw in U within the underlying semantics.We can also use labels to specify the wayin which points are related in a particular model;for example,the relational formulaw:R w tells us that the world w is accessible from w in a Kripke model(which is aparticular,simple,instance of the general models of the form U,B,ν ).Labelled deduction systems have been given for several non-classical logics,e.g.[1, 2,3,4,8,10,12,14,16,19,28].Research on labelling has focused not only on the design of systems for specific logics,but also,more generally,on the characteriza-tion of the classes of logics that can be formalized this way.General properties and limitations of labelling techniques have also been investigated.For example,[4,28] highlight a tradeoffbetween limitations and properties:if we reason on the semantic information provided by labelling using Horn-style rules,then we are able to present only a subset of all possible non-classical logics,but we can still capture many of the most common ones and,more importantly,labelling provides an efficient gen-eral method for establishing the metatheoretical properties of these logics,including their completeness,decidability and computational complexity.Moreover,[4,28]also contain some preliminary results on combining labelled deduction systems. Contributions The main contribution of this paper is an account of how labelled deduction systems can befibred.We concentrate on logics with a propositional basis, endowed with labelled deduction systems,and where labels provide additional infor-mation of a semantic nature.Specifically,our contributions can be summarized as follows.Our approach is general and we give here a novel(algebraic)presentation of labelled deduction systems that provides a suitable basis for defining theirfibring,and that subsumes,as simple special cases,the more standard labelled natural deduction systems of our previous work[3,4,28].Based on this presentation,we then give a categorial definition of(unconstrained and constrained by symbol sharing)fibring of labelled deduction systems.Afterwards,we adapt the general semantics advocated for Hilbert systems in[29]to the case of labelled deduction systems;hence,the gen-eral approach that we consider here subsumes our previous work also at the semantic level(the Kripke-style semantics that we gave for labelled natural deduction systems is a simple,special case of the general semantics).Then we establish the conditions under which our systems are sound and complete with respect to the general seman-tics for the corresponding logics,and define(both forms of)fibring at the semantic level.Finally,building on the completeness theorem,we establish requirements on the given logics and systems so that completeness is preserved by(both forms of)fibring. Preservation of other metatheoretical properties such as thefinite model property and decidability will be subject of future work.Organization The remainder of this paper is organized as follows.In Section2we introduce labelled deduction systems at the abstract level we need and theirfibrings. In Section3we focus on semantics,and in Section4we prove the completeness theorem and the preservation results.In Section5we draw conclusions and discuss related and future work.2Labelled deduction systemsIn this section we introduce our labelled deduction systems for logics with a proposi-tional basis.In Section2.1we define the language of our systems,specifying how to build formulae and judgements.Then,leading up to the definition of consequence,inSection2.2we define inference rules and derivations in our systems,giving in passing some examples for modal and temporal logics.Finally,in Section2.3we introduce unconstrained and constrainedfibring as categorial constructions and illustrate them with an example from modal logic.2.1LanguageWe introduce the notions of signature,formula and judgement.Definition1A signature is a pairΣ= C,O of families of language constructors, with C={C k}k∈N where each C k is a set,and O={O k}k∈N+where each O k is a set.The elements of C k are formula operators(or connectives)of arity k,and the elements of O k are relational operators of arity k.Notation2Wefix once and for all a family of schema variablesΞ={Ξj}j∈{lb,wf}, whereΞlb is a set of label schema variables andΞwf is a set of(well-formed)formula schema variables.Formulae in our systems are then built fromΣandΞaccording to the following definition.Definition3The set L(C,Ξwf)of schema formulae is defined inductively as fol-lows:(i)ξ∈L(C,Ξwf)for allξ∈Ξwf;(ii)c∈L(C,Ξwf)for all c∈C0;and (iii)c(φ1,...,φk)∈L(C,Ξwf)for all c∈C k andφ1,...,φk∈L(C,Ξwf).The set L(O,Ξlb)of relational schema formulae is defined as the set of o(w1,...,w k) for all o∈O k and w1,...,w k∈Ξlb.The set L(Σ,Ξ)of labelled schema formulae is L(Σ,Ξ)={w:ϕ|w∈Ξlb andϕ∈L(C,Ξwf)∪L(O,Ξlb)}. Notation4We write lb(∆)to denote the set of all labels(label schema variables) that appear in the formulae of a set∆⊆L(Σ,Ξ)of labelled schema formulae.The examples below,in particular Examples10and11,will illustrate the idea behind these definitions:the connectives are in a many-to-many relationship with the relational operators.This is a generalization of the techniques adopted in[3,4,28], where labelled natural deduction systems for several non-classical logics are given by associating each non-classical connective of arity n with a syntactic representative of a semantic relation of arity n+1.1To illustrate this,take the simple example of modal logics.We can evaluate formulae built using the unary modal connectives 2and3in terms of two distinct binary semantic relations R2and R3,which we represent in a modal labelled natural deduction system by means of formulae of the form w:R2w and w:R3w .Moreover,in the case that the logic we are considering is, for example,the basic mono-modal logic K,we have that R2and R3coincide so that in our system for that logic the connectives2and3are associated with the same binary relational operator R.Similar observations apply for the other non-classical logics considered in[3,4,28],e.g.binary relevant implication is associated with a ternary“compossibility”relation.1Note that the techniques of[3,4,28]are in turn an adaptation and extension of the principles of“Boolean algebra with operators”[22]and of“gaggle theory”[13].In[3,4,28]we restricted our attention to relationships between connectives and relational operators that are bijective relationships and where the arities arefixed beforehand.But there are logics in which this is not the case;a notable example is given by temporal logics,where the binary“until”connective is associated with a relation that is also binary(cf.Example11).Hence,here we loosen these restrictions: we allow for a liberal relationship between connectives and relational operators,and we do notfix their arities beforehand.There is however an aspect in which we follow the restrictions of previous work more closely,and we do so in order to simplify the development.Definition3says that in our systems we consider two distinct kinds of unlabelled schema formulae,so that the meaning of a labelled schema formula w:ϕwill explicitly depend onϕ.If ϕis a schema formula c(φ1,...,φk),then w:ϕmeans that the formula c(φ1,...,φk) holds at the world denoted by w.Ifϕis a relational schema formula o(w1,...,w k), then w:ϕmeans that the worlds denoted by w1,...,w k are in the relation denoted by o at the world denoted by w.For example,when o is the accessibility relation R of modal logics,w1:R w2means that the expression“w2is accessible”,denoted by R w2,holds at w1,i.e.that at w1we can see w2.We do not admit“hybrid”formulae where the operators can be freely mixed, e.g.c1(o1(c2(w1,w2))).Formulae of this form are used for instance in presentations of non-classical logics based on hybrid languages,e.g.[6],or on semantic embeddings (i.e.on translations intofirst or higher-order logic;see,for example,[23]).Moreover, our relational formulae are atomic and cannot be composed.A consequence of these restrictions is that we will not be able to give labelled deduction systems for all logics that can be presented using hybrid languages,semantic embeddings or other similar approaches based on labelling or translations.However, like for[3,4,28],to which the reader is referred for further details and comparison with related approaches,the restricted language that we adopt will suffice to give labelled deduction systems for several of the most common non-classical logics;in fact,thanks to our generalizations,we will be able to give labelled deduction systems for many more logics than the ones considered in previous work.2Returning to the technical development,we now define what is a judgement. Loosely speaking,a judgement is a relation between a labelled schema formulaδ, afinite set of labelled schema formulae∆,and afinite set of label schema variables Φ,which will allow us to define when a formula follows from a set of formulae(cf.Def-initions21and22),and also to represent intermediate steps in a derivation where fresh variables may occur.Definition5A judgement ∆,δ,Φ is a triple where∆∈℘fin L(Σ,Ξ)is afinite set of labelled schema formulae,δ∈L(Σ,Ξ)is a labelled schema formula,andΦ⊆Ξlb is a finite set of label schema variables,which will represent fresh variables in a derivation.Notation6We write J(Σ,Ξ)to denote the set of all judgements.Moreover,we 2It is then interesting to investigate if our generalizations allow us to inherit the properties shown for the labelled natural deduction systems of previous work,e.g.normalization of derivations and the subformula property.We conjecture that this is the case,but leave a detailed analysis for future work.represent a judgementζ= ∆,δ,{w1,...,w k} by∆,δ w1,...,w k,and we also denote∆by Ant(ζ),δby Cons(ζ),and{w1,...,w k}by Fresh(ζ).Fur-thermore,when Fresh(ζ)is empty,we representζby writing simply ∆,δ .2.2Deduction and consequenceIn order to define a consequence relation for proving assertions using hypotheses, which we will do in Prop/Definition27,we need to say when a judgement follows (i.e.can be derived)from a set of judgements.Hence,we now introduce inference rules and define our labelled deduction systems.Definition7An inference rule is a pair Prem,Conc where Prem∈℘fin J(Σ,Ξ)is afinite set of premise-judgements,and the conclusion-judgement Conc∈J(Σ,Ξ)is such that Ant(Conc)=∅and Fresh(Conc)=∅. Notation8We represent an inference rule r= {ζ1,...,ζk},ζ byζ1···ζkr,ζand we denote the premises{ζ1,...,ζk}by Prem(r)and the conclusionζby Conc(r). We write R(Σ,Ξ)to denote the set of all inference rules. Definition9A labelled deduction system(lds)is a pair Σ,D whereΣis a signature and D⊆R(Σ,Ξ).Even though we imposed some simplifying restrictions on signatures,e.g.that schema formulae cannot be mixed with(atomic)relational schema formulae,our inference rules and lds’s are general enough to subsume(as simple instances)the labelled natural deduction systems of[3,4,28]for modal,relevance and other non-classical logics.3To illustrate this,we now give lds’s for the mono-modal logic K and its extensions, and for basic temporal logic with⊥,→and the until operator U.In the case of modal logics,we can give lds’s that are indeed simple notational variants of the labelled natural deduction systems of previous work,and which contain elimination and introduction rules for each connective c(denoted by c E and c I),except for⊥,for which we give only the rule⊥E.3By natural deduction systems we mean,as is usual,systems for proof under assumption that consist of introduction and elimination rules for each of the connectives except falsum,i.e.⊥,for which only an elimination rule is given[27].These rules define the meaning of each connective, specifying how it is introduced in a formula or eliminated from it.Our lds’s subsume labelled natural deduction systems because we do not commit ourselves here to such requirements on the rules but allow for the more general form of rules of Definition7.For example,while we do require that our rules are single-conclusioned,we do not require that they necessarily have the form that makes them introduction or elimination rules.Related to this,it is interesting to investigate whether our general approach generalizes,in a similar way,other forms of labelled Gentzen-style systems such as labelled tableaux or sequent systems;we conjecture that,with minor modifications,this is indeed the case but leave a detailed analysis for future work.Example10An lds Σ,D for the mono-modal logic K is defined as follows:Σ= C,O is such that C0=Π∪{⊥}whereΠis some set of propositional symbols, C1={2},C2={→},and O1={R};D contains the rules:{w:ξ→⊥},w :⊥∅,w:ξ ⊥E, ∅,w:ξ1→ξ2 ∅,w:ξ1∅,w:ξ2 →E, {w:ξ1},w:ξ2∅,w:ξ1→ξ2 →I,∅,w:2ξ ∅,w:R w∅,w :ξ 2E, {w:R w },w :ξ w∅,w:2ξ 2I.By considering the rule2I(2-Introduction),we can now informally explain the role of thefinite set of fresh label schema variables.(We will give a formal expla-nation after Definition19below.)Intuitively,the rule2I says that if for every w accessible from w we haveξ(i.e.w :ξfollows from w:R w with w fresh),then wecan conclude that in w we have2ξ(i.e.w:2ξ).In other words,the universal quan-tification corresponds to the side condition that w is fresh,and the antecedent of the premise-judgement requires that w is accessible from w.Note also that,given C,we can define other formula operators using standard abbreviations,e.g.¬ξ≡abrv(ξ→⊥),ξ1∧ξ2≡abrv¬(ξ1→¬ξ2),and3ξ≡abrv¬2¬ξ. The inference rules for these connectives are then derived from those for the primitive ones in C,as we show for instance in Example24for3elimination.Systems for other modal logics extending mono-modal K are obtained by extending the lds for K with rules expressing properties of R.For example,we obtain lds’s for T and K4by respectively extending the lds for K with the rules∅,w:R w refland ∅,w:R w ∅,w :R w∅,w:R w trans,we obtain an lds for S4by extending the lds for K with both refland trans,and an lds for S5by further adding a rule for the Euclidean property,e.g.∅,w:R w ∅,w:R w∅,w :R w eucl.More generally,we can extend our lds’s with Horn-style rules similar to the“relational rules”of[3,4,28].That is,with rules of the form∅,w1:ϕ1 ··· ∅,w n:ϕn∅,w:ϕwhereϕi is a relational schema formula for each i such that0≤i≤n.Since these example labelled deduction systems are not much different from the ones in[3,4,28],we refer the reader to these works for further examples of systems for modal and other non-classical logics,most notably relevance logics.4The following 4Note that the guarantee that our lds’s for K and its extensions are indeed deduction systems for these logics,i.e.that they are sound and complete with respect to the standard Kripke semantics for these logics,follows then trivially by the soundness and completeness of the labelled natural deduction systems of previous work.example,on the other hand,shows that the general approach taken here allows us to give a labelled(natural)deduction system for basic temporal logic,which was not possible with the formal machinery of previous work.Example11An lds Σ,D for basic temporal logic(with⊥,→,and the until opera-tor U associated with a binary relational operator R)is defined as follows:Σ= C,O is such that C0=Π∪{⊥}whereΠis some set of propositional symbols,C2={→,U} and O1={R};D contains rules⊥E,→E,→I,trans,and the following rules for U: ∅,w:ξ1Uξ2 ∅,w:R w {w:R w ,w :ξ2},w :R w w∅,w :ξ1 U E1,∅,w:ξ1Uξ2 {w:R w ,w :ξ2},w :ξ3 w∅,w :ξ3 U E2,∅,w :ξ2 {w:R w ,w :R w },w :ξ1 w∅,w:ξ1Uξ2 U I.Note,however,that due to the restrictions we imposed on our language we are not able to give lds’s for extensions of this logic where time is linear and/or discrete, which would require us to introduce connectives(e.g.disjunction)with which we can compose relational formulae.Moreover,even though here we can give rulesζ1···ζkrζ0in which we mix judgementsζi,where Cons(ζi)is a labelled schema formula,with judgementsζj,where Cons(ζj)is a labelled relational schema formula,there are other logics that require further interaction between formula and relational operators.That is,there are logics that require us explicitly to consider hybrid formulae,in which operators can be mixed freely.5We now motivate the following definitions.The objective is to say when a formula γis derived from a set of formulaeΓin an lds Σ,D ,i.e.Γ Σ,D γ.We will say that this is the case when the judgement Γ,γ,∅ is derived from the empty set of judgements.For this purpose we have to definefirst what it means that a judgement ζis derived from a set of judgementsΘin an lds Σ,D ,i.e.Θ∼ Σ,D ζ,and we do so after introducing some basic notions such as substitutions,instantiations and derivation trees.Definition12A substitution is a pairσ= σlb,σwf ,whereσlb:Ξlb→Ξlb and σwf:Ξwf→L(C,Ξwf)are maps called respectively label substitution and formula substitution.5In other words,we allow mixing of operators at the metalevel,by having rules that mix judge-ments with different kinds of formulae as conclusions,but we forbid mixing of operators at the object level,i.e.inside formulae.Note also that although the inference rules we give here are more general than the ones in[3,4,28],the above limitations are a consequence of the results reported in these works as,mutatis mutandis,the observations made there apply straightforwardly in this setting.As we remarked above,labelled deduction systems built using an extended language will be subject of future work.Notation13We write Sub(Σ,Ξ)for the set of all substitutions,and id for the identity substitution onΞ.Since our inference rules are schematic,to be able to carry out derivations we need to define the concepts of substitution for a rule and instantiation.For the former we need to say when two assignments are equivalent up to a particular set of labels. Definition14Letσandσ be substitutions andΦ⊆Ξlb be a set of labels.We saythatσandσ areΦco-equivalent,in symbolsσ≡Φσ ,iffσwf=σ wf andσlb(w)=σ lb(w)for each w∈Ξlb such that w∈Φ. Definition15Let r= {ζi}1≤i≤k,ζ be an inference rule.An r-substitution is a pair {σi}1≤i≤k,σ such thatσi≡Fresh(ζi)σfor each i=1,...,k. Notation16In the following,given a labelled schema formulaδ,a set of labelled schema formulae∆and a substitutionσ,we denote byδσthe labelled schema formula that results fromδby the simultaneous replacement of its schema variables by their value given byσ.By extension,∆σdenotes the set consisting of allγσfor each γ∈∆.Similarly,given a label w and a set of labelsΦ,we denote by wσthe label σlb(w),and denote byΦσthe set consisting of all wσfor each w∈Φ. Definition17The judgement Γ,γ,Υ is an instance of the judgement ∆,δ,Φ by the substitutionσiff(i)δσisγ,(ii)Φσ⊆Υ,(iii)∆σ⊆Γ,and(iv)wσ∈(Ξlb\{w})σfor each w∈Φ. Notation18We denote by Inst(ζ,σ)the set of instances of a judgementζbyσ. Definition19The pair { Γi,γi,Υi }1≤i≤k, Γ,γ,Υ is an instance of r= { ∆i,δi,Φi }1≤i≤k, ∅,δ,∅ by an r-substitution {σi}1≤i≤k,σ iffδσisγ,and for each i,with 1≤i≤k,• Γi,γi,Υi ∈Inst( ∆i,δi,Φi ,σi),•lb(Γ)∩Φiσi=∅,•Γi=Γ∪∆iσi,and•Υi\Φiσi=Υ.Observe that,reasoning backwards from goal to axioms,i.e.applying rules from conclusion to premises,the image of any fresh variable in a premise should not have been already used in the derivation we are building,and that the hypotheses in the conclusion are transferred to the premises,and so are(more strictly)the fresh variables.Consider again the rule{w:R w },w :ξ w∅,w:2ξ 2I.The meaning of the“fresh”label schema variable w can now be specified formally as follows:any instantiation of w is a variable not present in the formulae of the instance of the judgement except in the ones indicated in the judgement under instantiation (i.e.w:R w and w :ξ.)Notation20We denote by Inst(r,s)the set of all rules that are instances of rule r by the r-substitution s. Definition21A judgementζis derivable from a set of judgementsΘin an lds Σ,D ,in symbolsΘ∼ Σ,D ζ,iffthere is a tree annotated by judgements such that(i)the annotation of the root isζ,and(ii)for each node,•the pair formed by the annotation of the node and the set of annotations of its successors is an instance of some rule of D,•or the node has no successors and its annotation is an axiom,i.e.it is of the form Γ∪{γ},γ,Υ ,•or it has no successors and there is an hypothesis ∆,δ,Φ ∈Θand a substitution σ≡Φid such that if its annotation has the form Γ,γ,Υ then∆σ⊆Γ, lb(∆∪{δ})σ∩Υ⊆Φσandγisδσ.A tree in the conditions of the previous definition will be called a derivation tree forΘ∼ Σ,D ζ.In the following,when there is no ambiguity,we will identify a node with its annotation.When it is not convenient to do so,we will refer to the annotation of a node x by a(x)and even by a T(x)when referring to the underlying tree T.We can nowfinally define what are derivations in our lds’s.Definition22A labelled schema formulaγis derivable from a set of labelled schema formulaeΓin an lds Σ,D ,in symbolsΓ Σ,D γ,iff∅∼ Σ,D Γ,γ . Notation23When no confusion arises,we will simply writeΘ∼ζandΓ γinstead ofΘ∼ Σ,D ζandΓ Σ,D γ,respectively.As an example,we now employ the derived rules for negation to derive rules for 3in our lds for the mono-modal logic K.All these derived rules are clearly also derivable in lds’s extending that for K.Example24It is easy to see that,in our lds for the mono-modal logic K, ∅,w:⊥ can be derived from ∅,w:¬ξ and ∅,w:ξ ,and that ∅,w:¬ξ can be derived from {w:ξ},w:⊥ .Hence,the following rules for negation are derivable:∅,w:¬ξ ∅,w:ξ∅,w:⊥ ¬E and {w:ξ},w:⊥ ∅,w:¬ξ ¬I.In(1)we derive ∅,w :ξ2 from the hypotheses {w :ξ1,w:R w },w :ξ2 w and ∅,w:3ξ1 .{w :ξ2→⊥},w:¬2¬ξ1 HYP(2){w :ξ2→⊥,w:R w },w :¬ξ1 w ¬I {w :ξ2→⊥},w:2¬ξ1 2I{w:ξ2→⊥},w:⊥ ¬E∅,w :ξ2 ⊥E(1){w:⊥→⊥,w:ξ2→⊥,w:ξ1,w:R w},w:ξ2→⊥ w AX(3)(2){w :⊥→⊥,w :ξ2→⊥,w :ξ1,w:R w },w :⊥ w →E{w :ξ2→⊥,w :ξ1,w:R w },w :⊥ w ⊥E{w :⊥→⊥,w :ξ2→⊥,w :ξ1,w:R w },w :ξ2 w HYP(3) Hence,the following rule for3elimination is derivable:∅,w:3ξ1 {w :ξ1,w:R w },w :ξ2 w∅,w :ξ2 3E.Similarly,we can derive the introduction rule∅,w :ξ ∅,w:R w∅,w:3ξ 3I,since we can easily show that{ ∅,w :ξ , ∅,w:R w }∼ ∅,w:3ξ Two remarks.First,note that3E inherits from2I a freshness side condition on a label schema variable:w is a new variable that is different from w and w ,and does not occur in any formula of the premise-judgement other than w:R w and w :ξ. Second,to illustrate the instantiation of rules by given substitutions,note that in the instantiation of2I(with straightforward substitutions)in the derivation(1)the antecedent of the conclusion(w :ξ2→⊥)is inherited in the premise,and that the other formula(w:R w )in the antecedent of the premise is an instantiation of the corresponding formula in the rule.We now prove two useful properties of derivations,which will allow us to introduce a consequence operator in Prop/Definition27.Wefirst show that derivations are monotonic,in the sense that if a labelled schema formulaγis derivable from a set of labelled schema formulaeΓ,thenγcan be derived also fromΓ∪Ψ,whereΨis an arbitrary set of labelled schema formulae.Then,in Lemma26,we show that derivations are idempotent,since if∅∼ Γ,ψ and∅∼ {ψ},γ then∅∼ Γ,γ . Lemma25For eachΨ⊆L(Σ,Ξ)andΥ⊆Ξlb we have∅∼ Γ∪Ψ,γ,Υ whenever ∅∼ Γ,γ .Proof Assuming that we are given a derivation tree for∅∼ Γ,γ ,we want to define a derivation tree for∅∼ Γ∪Ψ,γ,Υ .The basic idea is to rename the fresh variables used in thefirst derivation so that no clash appears with the variables occurring inΨandΥ.This is achieved by introducing a family of substitutions that for each node will carry out the renaming of the variables of the judgement in that node.Consider a derivation tree T for∅∼ Γ,γ ,and for each node x define a substitu-tionρx such that•the substitution of the node root is id,and。
Problem-solvingb...
Neurocomputing44–46(2002)735–742/locate/neucomProblem-solving behavior in a system modelof the primate neocortexAlan H.BondCalifornia Institute of Technology,Mailstop136-93,Pasadena,CA91125,USAAbstractWe show how our previously described system model of the primate neocortex can be extended to allow the modeling of problem-solving behaviors.Speciÿcally,we model di erent cognitive strategies that have been observed for human subjects solving the Tower of Hanoi problem. These strategies can be given a naturally distributed form on the primate neocortex.Further, the goal stacking used in some strategies can be achieved using an episodic memory module corresponding to the hippocampus.We can give explicit falsiÿable predictions for the time sequence of activations of di erent brain areas for each strategy.c 2002Published by Elsevier Science B.V.Keywords:Neocortex;Modular architecture;Perception–action hierarchy;Tower of Hanoi;Problem solving;Episodic memory1.Our system model of the primate neocortexOur model[4–6]consists of a set of processing modules,each representing a corti-cal area.The overall architecture is a perception–action hierarchy.Data stored in each module is represented by logical expressions we call descriptions,processing within each module is represented by sets of rules which are executed in parallel and which construct new descriptions,and communication among modules consists of the trans-mission of descriptions.Modules are executed in parallel on a discrete time scale, corresponding to20ms.During one cycle,all rules are executed once and all inter-module transmission of descriptions occurs.Fig.1depicts our model,as a set of cor-tical modules and as a perception–action hierarchy system diagram.The action of theE-mail address:***************.edu(A.H.Bond).0925-2312/02/$-see front matter c 2002Published by Elsevier Science B.V.PII:S0925-2312(02)00466-6736 A.H.Bond/Neurocomputing44–46(2002)735–742Fig.1.Our system model shown in correspondence with the neocortex,and as a perception–action hierarchy.system is to continuously create goals,prioritize goals,and elaborate the highest priority goals into plans,then detailed actions by propagating descriptions down the action hierarchy,resulting in a stream of motor commands.(At the same time,perception of the environment occurs in a ow of descriptions up the perception hierarchy.Perceived descriptions condition plan elaboration,and action descriptions condition perception.) This simple elaboration of stored plans was su cient to allow is to demonstrate simple socially interactive behaviors using a computer realization of our model.A.H.Bond/Neurocomputing44–46(2002)735–7427372.Extending our model to allow solution of the Tower of Hanoi problem2.1.Tower of Hanoi strategiesThe Tower of Hanoi problem is the most studied,and strategies used by human subjects have been captured as production rule systems[9,1].We will consider the two most frequently observed strategies—the perceptual strategy and the goal recursion strategy.In the general case,reported by Anzai and Simon[3],naive subjects start with an initial strategy and learn a sequence of strategies which improve their performance. Our two strategies were observed by Anzai and Simon as part of this learning sequence. Starting from Simon’s formulation[8],we were able to represent these two strategies in our model,as follows:2.2.Working goalsSince goals are created dynamically by the planning activity,we needed to extend our plan module to allow working goals as a description type.This mechanism was much better than trying to use the main goal module.We can limit the number of working goals.This would correspond to using aÿxed size store,corresponding to working memory.The module can thus create working goals and use the current working goals as input to rules.Working goals would be held in dorsal prefrontal areas,either as part of or close to the plan module.Main motivating topgoals are held in the main goal module corresponding to anterior cingulate.2.3.Perceptual tests and mental imageryThe perceptual tests on the external state,i.e.the state of the Tower of Hanoi apparatus,were naturally placed in a separate perception module.This corresponds to Kosslyn’s[7]image store.The main perceptual test needed is to determine whether a proposed move is legal.This involves(a)making a change to a stored perceived representation corresponding to making the proposed move,and(b)making a spatial comparison in this image store to determine whether the disk has been placed on a smaller or a larger one.With these two extensions,we were able to develop a representation of the perceptual strategy,depicted in Fig.2.3.Episodic memory and its use in goal stackingIn order to represent the goal recursion strategy,we need to deal with goal stacking, which is represented by push and pop operations in existing production rule represen-tations.Since we did not believe that a stack with push and pop operations within a module is biologically plausible,we found an equivalent approach using an episodic memory module.738 A.H.Bond/Neurocomputing44–46(2002)735–742Fig.2.Representation of the perceptual strategy on our brain model.This module creates associations among whatever inputs it receives at any given time, and it sends these associations as descriptions to be stored in contributing modules. In general,it will create episodic representations from events occurring in extended temporal intervals;however,in the current case we only needed simple association. In the Tower of Hanoi case,the episode was simply taken to be an association between the current working goal and the previous,parent,working goal.We assume that these two working goals are always stored in working memory and are available to the plan module.The parent forms a context for the working goal.The episode description is formed in the episodic memory module and transmitted to the plan module where it is stored.The creation of episodic representations can proceed in parallel with the problem solving process,and it can occur automatically or be requested by the plan module.Rules in the plan module can retrieve episodic descriptions usingA.H.Bond/Neurocomputing44–46(2002)735–742739the current parent working goal,and can replace the current goal with the current parent,and the current parent with its retrieved parent.Thus the working goal context can be popped.This representation is more general than a stack,since any stored episode could be retrieved,including working goals from episodes further in the past. Such e ects have,in fact,been reported by Van Lehn et al.[10]for human subjects. With this additional extension,we were able to develop a representation of the goal recursion strategy,depicted in Fig.3.Descriptions of episodes are of the form con-text(goal(G),goal context(C)).goal(G)being the current working goal and goal context(C)the current parent working goal.Theÿgure shows a slightly more general version,where episodes are stored both in the episodic memory module and the plan module.This allows episodes that have not yet been transferred to the cortex to be used.We are currently working on extending our model to allow the learning a sequence of strategies as observed by Anzai and Simon.This may result in a di erent representation of these strategies,and di erent performance.740 A.H.Bond/Neurocomputing44–46(2002)735–742during perceptual analysis during movementP MFig.4.Predictions of brain area activation during Tower of Hanoi solving.4.Falsiÿable predictions of brain area activationFor the two strategies,we can now generate detailed predictions of brain area acti-vation sequences that should be observed during the solution of the Tower of Hanoi ing our computer realization,we can generate detailed predictions of activa-tion levels for each time step.Since there are many adjustable parameters and detailed assumptions in the model,it is di cult toÿnd clearly falsiÿable predictions.However, we can also make a simpliÿed and more practical form of prediction by classifying brain states into four types,shown in Fig.4.Let us call these types of states G,E,P and M,respectively.Then,for example,the predicted temporal sequences of brain state types for3disks are:A.H.Bond/Neurocomputing44–46(2002)735–742741For the perceptual strategy:G0;G;E;P;G;E;P;G;E;P;E;M;P;G;E;P;G;E;P;E;M;P;G;E;P;G;E;P;E;M;P;G;E;P;E;M;P;G;E;P;G;E;P;E;M;P;G;E;P;E;M;P;G;E;P;E;M;P;G0:and for the goal recursion strategy:G0;G;E;P;G+;E;P;G+;E;P;E;M;P;G∗;E;P;E;M;P;G∗;E;P;G+;E;P;E;M;P;G∗;E;P;E;M;P;G;E;P;G+;E;P;E;M;P;G∗;E;P;E;M;E;G;E;P;E;M;P;G0: We can generate similar sequences for di erent numbers of disks and di erent strate-gies.The physical moves of disks occur during M steps.The timing is usually about 3:5s per physical move,but the physical move steps probably take longer than the average cognitive step.If a physical move takes1:5s,this would leave about300ms per cognitive step.The perceptual strategy used is an expert strategy where the largest disk is always selected.We assume perfect performance;when wrong moves are made,we need a theory of how mistakes are made,and then predictions can be generated.In the goal recursion strategy,we assume the subject is using perceptual tests for proposed moves, and is not working totally from memory.G indicates the creation of a goal,G+a goal creation and storing an existing goal(push),and G∗the retrieval of a goal(pop). Anderson et al.[2]have shown that pushing a goal takes about2s,although we have taken creation of a goal to not necessarily involve pushing.For us,pushing only occurs when a new goal is created and an existing goal has to be stored.G0is activity relating to the top goal.It should be noted that there is some redundancy in the model,so that,if a mismatch to experiment is found,it would be possible to make some changes to the model to bring it into better correspondence with the data.For example,the assignment of modules to particular brain areas is tentative and may need to be changed.However, there is a limit to the changes that can be made,and mismatches with data could falsify the model in its present form.AcknowledgementsThis work has been partially supported by the National Science Foundation,Informa-tion Technology and Organizations Program managed by Dr.Les Gasser.The author would like to thank Professor Pietro Perona for his support,and Professor Steven Mayo for providing invaluable computer resources.References[1]J.R.Anderson,Rules of the Mind,Lawrence Erlbaum Associates,Hillsdale,NJ,1993.[2]J.R.Anderson,N.Kushmerick,C.Lebiere,The Tower of Hanoi and Goal structures,in:J.R.Anderson(Ed.),Rules of the Mind,Lawrence Erlbaum Associates,Hillsdale,New Jersey,1993,pp.121–142.742 A.H.Bond/Neurocomputing44–46(2002)735–742[3]Y.Anzai,H.A.Simon,The theory of learning by doing,Psychol.Rev.86(1979)124–140.[4]A.H.Bond,A computational architecture for social agents,Proceedings of Intelligent Systems:ASemiotic Perspective,An International Multidisciplinary Conference,National Institute of Standards and Technology,Gaithersburg,Maryland,USA,October20–23,1996.[5]A.H.Bond,A system model of the primate neocortex,Neurocomputing26–27(1999)617–623.[6]A.H.Bond,Describing behavioral states using a system model of the primate brain,Am.J.Primatol.49(1999)315–388.[7]S.Kosslyn,Image and Brain,MIT Press,Cambridge,MA,1994.[8]H.A.Simon,The functional equivalence of problem solving skills,Cognitive Psychol.7(1975)268–288.[9]K.VanLehn,Rule acquisition events in the discovery of problem-solving strategies,Cognitive Sci.15(1991)1–47.[10]K.VanLehn,W.Ball,B.Kowalski,Non-LIFO execution of cognitive procedures,Cognitive Sci.13(1989)415–465.Alan H.Bond was born in England and received a Ph.D.degree in theoretical physics in1966from Imperial College of Science and Technology,University of London.During the period1969–1984,he was on the faculty of the Computer Science Department at Queen Mary College,London University,where he founded and directed the Artiÿcial Intelligence and Robotics Laboratory.Since1996,he has been a Senior Scientist and Lecturer at California Institute of Technology.His main research interest concerns the system modeling of the primate brain.。
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英语专业八级考试TEM-8阅读理解练习册（1）(英语专业2012级)UNIT 1Text AEvery minute of every day, what ecologist生态学家James Carlton calls a global ―conveyor belt‖, redistributes ocean organisms生物.It’s planetwide biological disruption生物的破坏that scientists have barely begun to understand.Dr. Carlton —an oceanographer at Williams College in Williamstown,Mass.—explains that, at any given moment, ―There are several thousand marine species traveling… in the ballast water of ships.‖ These creatures move from coastal waters where they fit into the local web of life to places where some of them could tear that web apart. This is the larger dimension of the infamous无耻的，邪恶的invasion of fish-destroying, pipe-clogging zebra mussels有斑马纹的贻贝.Such voracious贪婪的invaders at least make their presence known. What concerns Carlton and his fellow marine ecologists is the lack of knowledge about the hundreds of alien invaders that quietly enter coastal waters around the world every day. Many of them probably just die out. Some benignly亲切地，仁慈地—or even beneficially — join the local scene. But some will make trouble.In one sense, this is an old story. Organisms have ridden ships for centuries. They have clung to hulls and come along with cargo. What’s new is the scale and speed of the migrations made possible by the massive volume of ship-ballast water压载水— taken in to provide ship stability—continuously moving around the world…Ships load up with ballast water and its inhabitants in coastal waters of one port and dump the ballast in another port that may be thousands of kilometers away. A single load can run to hundreds of gallons. Some larger ships take on as much as 40 million gallons. The creatures that come along tend to be in their larva free-floating stage. When discharged排出in alien waters they can mature into crabs, jellyfish水母, slugs鼻涕虫，蛞蝓, and many other forms.Since the problem involves coastal species, simply banning ballast dumps in coastal waters would, in theory, solve it. Coastal organisms in ballast water that is flushed into midocean would not survive. Such a ban has worked for North American Inland Waterway. But it would be hard to enforce it worldwide. Heating ballast water or straining it should also halt the species spread. But before any such worldwide regulations were imposed, scientists would need a clearer view of what is going on.The continuous shuffling洗牌of marine organisms has changed the biology of the sea on a global scale. It can have devastating effects as in the case of the American comb jellyfish that recently invaded the Black Sea. It has destroyed that sea’s anchovy鳀鱼fishery by eating anchovy eggs. It may soon spread to western and northern European waters.The maritime nations that created the biological ―conveyor belt‖ should support a coordinated international effort to find out what is going on and what should be done about it. (456 words)1.According to Dr. Carlton, ocean organism‟s are_______.A.being moved to new environmentsB.destroying the planetC.succumbing to the zebra musselD.developing alien characteristics2.Oceanographers海洋学家are concerned because_________.A.their knowledge of this phenomenon is limitedB.they believe the oceans are dyingC.they fear an invasion from outer-spaceD.they have identified thousands of alien webs3.According to marine ecologists, transplanted marinespecies____________.A.may upset the ecosystems of coastal watersB.are all compatible with one anotherC.can only survive in their home watersD.sometimes disrupt shipping lanes4.The identified cause of the problem is_______.A.the rapidity with which larvae matureB. a common practice of the shipping industryC. a centuries old speciesD.the world wide movement of ocean currents5.The article suggests that a solution to the problem__________.A.is unlikely to be identifiedB.must precede further researchC.is hypothetically假设地，假想地easyD.will limit global shippingText BNew …Endangered‟ List Targets Many US RiversIt is hard to think of a major natural resource or pollution issue in North America today that does not affect rivers.Farm chemical runoff残渣, industrial waste, urban storm sewers, sewage treatment, mining, logging, grazing放牧,military bases, residential and business development, hydropower水力发电,loss of wetlands. The list goes on.Legislation like the Clean Water Act and Wild and Scenic Rivers Act have provided some protection, but threats continue.The Environmental Protection Agency (EPA) reported yesterday that an assessment of 642,000 miles of rivers and streams showed 34 percent in less than good condition. In a major study of the Clean Water Act, the Natural Resources Defense Council last fall reported that poison runoff impairs损害more than 125,000 miles of rivers.More recently, the NRDC and Izaak Walton League warned that pollution and loss of wetlands—made worse by last year’s flooding—is degrading恶化the Mississippi River ecosystem.On Tuesday, the conservation group保护组织American Rivers issued its annual list of 10 ―endangered‖ and 20 ―threatened‖ rivers in 32 states, the District of Colombia, and Canada.At the top of the list is the Clarks Fork of the Yellowstone River, whereCanadian mining firms plan to build a 74-acre英亩reservoir水库，蓄水池as part of a gold mine less than three miles from Yellowstone National Park. The reservoir would hold the runoff from the sulfuric acid 硫酸used to extract gold from crushed rock.―In the event this tailings pond failed, the impact to th e greater Yellowstone ecosystem would be cataclysmic大变动的，灾难性的and the damage irreversible不可逆转的.‖ Sen. Max Baucus of Montana, chairman of the Environment and Public Works Committee, wrote to Noranda Minerals Inc., an owner of the ― New World Mine‖.Last fall, an EPA official expressed concern about the mine and its potential impact, especially the plastic-lined storage reservoir. ― I am unaware of any studies evaluating how a tailings pond尾矿池，残渣池could be maintained to ensure its structural integrity forev er,‖ said Stephen Hoffman, chief of the EPA’s Mining Waste Section. ―It is my opinion that underwater disposal of tailings at New World may present a potentially significant threat to human health and the environment.‖The results of an environmental-impact statement, now being drafted by the Forest Service and Montana Department of State Lands, could determine the mine’s future…In its recent proposal to reauthorize the Clean Water Act, the Clinton administration noted ―dramatically improved water quality since 1972,‖ when the act was passed. But it also reported that 30 percent of riverscontinue to be degraded, mainly by silt泥沙and nutrients from farm and urban runoff, combined sewer overflows, and municipal sewage城市污水. Bottom sediments沉积物are contaminated污染in more than 1,000 waterways, the administration reported in releasing its proposal in January. Between 60 and 80 percent of riparian corridors (riverbank lands) have been degraded.As with endangered species and their habitats in forests and deserts, the complexity of ecosystems is seen in rivers and the effects of development----beyond the obvious threats of industrial pollution, municipal waste, and in-stream diversions改道to slake消除the thirst of new communities in dry regions like the Southwes t…While there are many political hurdles障碍ahead, reauthorization of the Clean Water Act this year holds promise for US rivers. Rep. Norm Mineta of California, who chairs the House Committee overseeing the bill, calls it ―probably the most important env ironmental legislation this Congress will enact.‖ (553 words)6.According to the passage, the Clean Water Act______.A.has been ineffectiveB.will definitely be renewedC.has never been evaluatedD.was enacted some 30 years ago7.“Endangered” rivers are _________.A.catalogued annuallyB.less polluted than ―threatened rivers‖C.caused by floodingD.adjacent to large cities8.The “cataclysmic” event referred to in paragraph eight would be__________.A. fortuitous偶然的，意外的B. adventitious外加的，偶然的C. catastrophicD. precarious不稳定的，危险的9. The owners of the New World Mine appear to be______.A. ecologically aware of the impact of miningB. determined to construct a safe tailings pondC. indifferent to the concerns voiced by the EPAD. willing to relocate operations10. The passage conveys the impression that_______.A. Canadians are disinterested in natural resourcesB. private and public environmental groups aboundC. river banks are erodingD. the majority of US rivers are in poor conditionText CA classic series of experiments to determine the effects ofoverpopulation on communities of rats was reported in February of 1962 in an article in Scientific American. The experiments were conducted by a psychologist, John B. Calhoun and his associates. In each of these experiments, an equal number of male and female adult rats were placed in an enclosure and given an adequate supply of food, water, and other necessities. The rat populations were allowed to increase. Calhoun knew from experience approximately how many rats could live in the enclosures without experiencing stress due to overcrowding. He allowed the population to increase to approximately twice this number. Then he stabilized the population by removing offspring that were not dependent on their mothers. He and his associates then carefully observed and recorded behavior in these overpopulated communities. At the end of their experiments, Calhoun and his associates were able to conclude that overcrowding causes a breakdown in the normal social relationships among rats, a kind of social disease. The rats in the experiments did not follow the same patterns of behavior as rats would in a community without overcrowding.The females in the rat population were the most seriously affected by the high population density: They showed deviant异常的maternal behavior; they did not behave as mother rats normally do. In fact, many of the pups幼兽，幼崽, as rat babies are called, died as a result of poor maternal care. For example, mothers sometimes abandoned their pups,and, without their mothers' care, the pups died. Under normal conditions, a mother rat would not leave her pups alone to die. However, the experiments verified that in overpopulated communities, mother rats do not behave normally. Their behavior may be considered pathologically 病理上，病理学地diseased.The dominant males in the rat population were the least affected by overpopulation. Each of these strong males claimed an area of the enclosure as his own. Therefore, these individuals did not experience the overcrowding in the same way as the other rats did. The fact that the dominant males had adequate space in which to live may explain why they were not as seriously affected by overpopulation as the other rats. However, dominant males did behave pathologically at times. Their antisocial behavior consisted of attacks on weaker male,female, and immature rats. This deviant behavior showed that even though the dominant males had enough living space, they too were affected by the general overcrowding in the enclosure.Non-dominant males in the experimental rat communities also exhibited deviant social behavior. Some withdrew completely; they moved very little and ate and drank at times when the other rats were sleeping in order to avoid contact with them. Other non-dominant males were hyperactive; they were much more active than is normal, chasing other rats and fighting each other. This segment of the rat population, likeall the other parts, was affected by the overpopulation.The behavior of the non-dominant males and of the other components of the rat population has parallels in human behavior. People in densely populated areas exhibit deviant behavior similar to that of the rats in Calhoun's experiments. In large urban areas such as New York City, London, Mexican City, and Cairo, there are abandoned children. There are cruel, powerful individuals, both men and women. There are also people who withdraw and people who become hyperactive. The quantity of other forms of social pathology such as murder, rape, and robbery also frequently occur in densely populated human communities. Is the principal cause of these disorders overpopulation? Calhoun’s experiments suggest that it might be. In any case, social scientists and city planners have been influenced by the results of this series of experiments.11. Paragraph l is organized according to__________.A. reasonsB. descriptionC. examplesD. definition12．Calhoun stabilized the rat population_________.A. when it was double the number that could live in the enclosure without stressB. by removing young ratsC. at a constant number of adult rats in the enclosureD. all of the above are correct13.W hich of the following inferences CANNOT be made from theinformation inPara. 1?A. Calhoun's experiment is still considered important today.B. Overpopulation causes pathological behavior in rat populations.C. Stress does not occur in rat communities unless there is overcrowding.D. Calhoun had experimented with rats before.14. Which of the following behavior didn‟t happen in this experiment?A. All the male rats exhibited pathological behavior.B. Mother rats abandoned their pups.C. Female rats showed deviant maternal behavior.D. Mother rats left their rat babies alone.15. The main idea of the paragraph three is that __________.A. dominant males had adequate living spaceB. dominant males were not as seriously affected by overcrowding as the otherratsC. dominant males attacked weaker ratsD. the strongest males are always able to adapt to bad conditionsText DThe first mention of slavery in the statutes法令，法规of the English colonies of North America does not occur until after 1660—some forty years after the importation of the first Black people. Lest we think that existed in fact before it did in law, Oscar and Mary Handlin assure us, that the status of B lack people down to the 1660’s was that of servants. A critique批判of the Handlins’ interpretation of why legal slavery did not appear until the 1660’s suggests that assumptions about the relation between slavery and racial prejudice should be reexamined, and that explanation for the different treatment of Black slaves in North and South America should be expanded.The Handlins explain the appearance of legal slavery by arguing that, during the 1660’s, the position of white servants was improving relative to that of black servants. Thus, the Handlins contend, Black and White servants, heretofore treated alike, each attained a different status. There are, however, important objections to this argument. First, the Handlins cannot adequately demonstrate that t he White servant’s position was improving, during and after the 1660’s; several acts of the Maryland and Virginia legislatures indicate otherwise. Another flaw in the Handlins’ interpretation is their assumption that prior to the establishment of legal slavery there was no discrimination against Black people. It is true that before the 1660’s Black people were rarely called slaves. But this shouldnot overshadow evidence from the 1630’s on that points to racial discrimination without using the term slavery. Such discrimination sometimes stopped short of lifetime servitude or inherited status—the two attributes of true slavery—yet in other cases it included both. The Handlins’ argument excludes the real possibility that Black people in the English colonies were never treated as the equals of White people.The possibility has important ramifications后果，影响.If from the outset Black people were discriminated against, then legal slavery should be viewed as a reflection and an extension of racial prejudice rather than, as many historians including the Handlins have argued, the cause of prejudice. In addition, the existence of discrimination before the advent of legal slavery offers a further explanation for the harsher treatment of Black slaves in North than in South America. Freyre and Tannenbaum have rightly argued that the lack of certain traditions in North America—such as a Roman conception of slavery and a Roman Catholic emphasis on equality— explains why the treatment of Black slaves was more severe there than in the Spanish and Portuguese colonies of South America. But this cannot be the whole explanation since it is merely negative, based only on a lack of something. A more compelling令人信服的explanation is that the early and sometimes extreme racial discrimination in the English colonies helped determine the particular nature of the slavery that followed. (462 words)16. Which of the following is the most logical inference to be drawn from the passage about the effects of “several acts of the Maryland and Virginia legislatures” (Para.2) passed during and after the 1660‟s?A. The acts negatively affected the pre-1660’s position of Black as wellas of White servants.B. The acts had the effect of impairing rather than improving theposition of White servants relative to what it had been before the 1660’s.C. The acts had a different effect on the position of white servants thandid many of the acts passed during this time by the legislatures of other colonies.D. The acts, at the very least, caused the position of White servants toremain no better than it had been before the 1660’s.17. With which of the following statements regarding the status ofBlack people in the English colonies of North America before the 1660‟s would the author be LEAST likely to agree?A. Although black people were not legally considered to be slaves,they were often called slaves.B. Although subject to some discrimination, black people had a higherlegal status than they did after the 1660’s.C. Although sometimes subject to lifetime servitude, black peoplewere not legally considered to be slaves.D. Although often not treated the same as White people, black people,like many white people, possessed the legal status of servants.18. According to the passage, the Handlins have argued which of thefollowing about the relationship between racial prejudice and the institution of legal slavery in the English colonies of North America?A. Racial prejudice and the institution of slavery arose simultaneously.B. Racial prejudice most often the form of the imposition of inheritedstatus, one of the attributes of slavery.C. The source of racial prejudice was the institution of slavery.D. Because of the influence of the Roman Catholic Church, racialprejudice sometimes did not result in slavery.19. The passage suggests that the existence of a Roman conception ofslavery in Spanish and Portuguese colonies had the effect of _________.A. extending rather than causing racial prejudice in these coloniesB. hastening the legalization of slavery in these colonies.C. mitigating some of the conditions of slavery for black people in these coloniesD. delaying the introduction of slavery into the English colonies20. The author considers the explanation put forward by Freyre andTannenbaum for the treatment accorded B lack slaves in the English colonies of North America to be _____________.A. ambitious but misguidedB. valid有根据的but limitedC. popular but suspectD. anachronistic过时的，时代错误的and controversialUNIT 2Text AThe sea lay like an unbroken mirror all around the pine-girt, lonely shores of Orr’s Island. Tall, kingly spruce s wore their regal王室的crowns of cones high in air, sparkling with diamonds of clear exuded gum流出的树胶; vast old hemlocks铁杉of primeval原始的growth stood darkling in their forest shadows, their branches hung with long hoary moss久远的青苔;while feathery larches羽毛般的落叶松,turned to brilliant gold by autumn frosts, lighted up the darker shadows of the evergreens. It was one of those hazy朦胧的, calm, dissolving days of Indian summer, when everything is so quiet that the fainest kiss of the wave on the beach can be heard, and white clouds seem to faint into the blue of the sky, and soft swathing一长条bands of violet vapor make all earth look dreamy, and give to the sharp, clear-cut outlines of the northern landscape all those mysteries of light and shade which impart such tenderness to Italian scenery.The funeral was over,--- the tread鞋底的花纹/ 踏of many feet, bearing the heavy burden of two broken lives, had been to the lonely graveyard, and had come back again,--- each footstep lighter and more unconstrained不受拘束的as each one went his way from the great old tragedy of Death to the common cheerful of Life.The solemn black clock stood swaying with its eternal ―tick-tock, tick-tock,‖ in the kitchen of the brown house on Orr’s Island. There was there that sense of a stillness that can be felt,---such as settles down on a dwelling住处when any of its inmates have passed through its doors for the last time, to go whence they shall not return. The best room was shut up and darkened, with only so much light as could fall through a little heart-shaped hole in the window-shutter,---for except on solemn visits, or prayer-meetings or weddings, or funerals, that room formed no part of the daily family scenery.The kitchen was clean and ample, hearth灶台, and oven on one side, and rows of old-fashioned splint-bottomed chairs against the wall. A table scoured to snowy whiteness, and a little work-stand whereon lay the Bible, the Missionary Herald, and the Weekly Christian Mirror, before named, formed the principal furniture. One feature, however, must not be forgotten, ---a great sea-chest水手用的储物箱,which had been the companion of Zephaniah through all the countries of the earth. Old, and battered破旧的，磨损的, and unsightly难看的it looked, yet report said that there was good store within which men for the most part respect more than anything else; and, indeed it proved often when a deed of grace was to be done--- when a woman was suddenly made a widow in a coast gale大风，狂风, or a fishing-smack小渔船was run down in the fogs off the banks, leaving in some neighboring cottage a family of orphans,---in all such cases, the opening of this sea-chest was an event of good omen 预兆to the bereaved丧亲者;for Zephaniah had a large heart and a large hand, and was apt有…的倾向to take it out full of silver dollars when once it went in. So the ark of the covenant约柜could not have been looked on with more reverence崇敬than the neighbours usually showed to Captain Pennel’s sea-chest.1. The author describes Orr‟s Island in a(n)______way.A.emotionally appealing, imaginativeB.rational, logically preciseC.factually detailed, objectiveD.vague, uncertain2.According to the passage, the “best room”_____.A.has its many windows boarded upB.has had the furniture removedC.is used only on formal and ceremonious occasionsD.is the busiest room in the house3.From the description of the kitchen we can infer that thehouse belongs to people who_____.A.never have guestsB.like modern appliancesC.are probably religiousD.dislike housework4.The passage implies that_______.A.few people attended the funeralB.fishing is a secure vocationC.the island is densely populatedD.the house belonged to the deceased5.From the description of Zephaniah we can see thathe_________.A.was physically a very big manB.preferred the lonely life of a sailorC.always stayed at homeD.was frugal and saved a lotText BBasic to any understanding of Canada in the 20 years after the Second World War is the country' s impressive population growth. For every three Canadians in 1945, there were over five in 1966. In September 1966 Canada's population passed the 20 million mark. Most of this surging growth came from natural increase. The depression of the 1930s and the war had held back marriages, and the catching-up process began after 1945. The baby boom continued through the decade of the 1950s, producing a population increase of nearly fifteen percent in the five years from 1951 to 1956. This rate of increase had been exceeded only once before in Canada's history, in the decade before 1911 when the prairies were being settled. Undoubtedly, the good economic conditions of the 1950s supported a growth in the population, but the expansion also derived from a trend toward earlier marriages and an increase in the average size of families; In 1957 the Canadian birth rate stood at 28 per thousand, one of the highest in the world. After the peak year of 1957, thebirth rate in Canada began to decline. It continued falling until in 1966 it stood at the lowest level in 25 years. Partly this decline reflected the low level of births during the depression and the war, but it was also caused by changes in Canadian society. Young people were staying at school longer, more women were working; young married couples were buying automobiles or houses before starting families; rising living standards were cutting down the size of families. It appeared that Canada was once more falling in step with the trend toward smaller families that had occurred all through theWestern world since the time of the Industrial Revolution. Although the growth in Canada’s population had slowed down by 1966 (the cent), another increase in the first half of the 1960s was only nine percent), another large population wave was coming over the horizon. It would be composed of the children of the children who were born during the period of the high birth rate prior to 1957.6. What does the passage mainly discuss?A. Educational changes in Canadian society.B. Canada during the Second World War.C. Population trends in postwar Canada.D. Standards of living in Canada.7. According to the passage, when did Canada's baby boom begin?A. In the decade after 1911.B. After 1945.C. During the depression of the 1930s.D. In 1966.8. The author suggests that in Canada during the 1950s____________.A. the urban population decreased rapidlyB. fewer people marriedC. economic conditions were poorD. the birth rate was very high9. When was the birth rate in Canada at its lowest postwar level?A. 1966.B. 1957.C. 1956.D. 1951.10. The author mentions all of the following as causes of declines inpopulation growth after 1957 EXCEPT_________________.A. people being better educatedB. people getting married earlierC. better standards of livingD. couples buying houses11.I t can be inferred from the passage that before the IndustrialRevolution_______________.A. families were largerB. population statistics were unreliableC. the population grew steadilyD. economic conditions were badText CI was just a boy when my father brought me to Harlem for the first time, almost 50 years ago. We stayed at the hotel Theresa, a grand brick structure at 125th Street and Seventh avenue. Once, in the hotel restaurant, my father pointed out Joe Louis. He even got Mr. Brown, the hotel manager, to introduce me to him, a bit punchy强力的but still champ焦急as fast as I was concerned.Much has changed since then. Business and real estate are booming. Some say a new renaissance is under way. Others decry责难what they see as outside forces running roughshod肆意践踏over the old Harlem. New York meant Harlem to me, and as a young man I visited it whenever I could. But many of my old haunts are gone. The Theresa shut down in 1966. National chains that once ignored Harlem now anticipate yuppie money and want pieces of this prime Manhattan real estate. So here I am on a hot August afternoon, sitting in a Starbucks that two years ago opened a block away from the Theresa, snatching抓取，攫取at memories between sips of high-priced coffee. I am about to open up a piece of the old Harlem---the New York Amsterdam News---when a tourist。
Fantastic Piece of Logic译文翻译
Fantastic Piece of Logic荒谬的的逻辑Sydney J. Harries One of the most fantastic pieces of logic I’ve ever seen in print is the rationale of capital punishment recently offered by Dr.George Crane, the only syndicated columnist who signs himself, “Ph.D., M.D.”我曾经在出版物中见过最荒谬的逻辑之一，是乔治克莱恩博士最近提出来的关于死刑的逻辑依据。
他是唯一一个署名哲学博士和医学博士的专栏作家。
He writes:”Clergymen should stress the fact that without capital punishment, there would be Christianity at all. If Jesus had not been sentenced to death on the cross, how could there be any Catholic or Protestant churches today? So Christianity owes its very existence to capital punishment.”他写道：“牧师应该强调这样一个事实,如果没有死刑,那么怎会有基督教呢。
如果耶稣没有被钉在十字架上判处死刑,今天怎么可能会有天主教或新教呢?因此，基督教的存在得益于死刑。
”With the use of this tremendous reasoning device, what cannot be justified in history? For instance, without the madness and despotism of King George I, there would have been no American Revolution and no United States of America.运用这种强大的推理方法，历史上还有什么不能被认定为是合理的？比如，没有国王乔治一世疯狂和专制，就不会有美国革命和美利坚合众国。
TEMPORAL LOGIC
TEMPORAL LOGICHeiko KrummUniversity of Dortmund, Department of Computer ScienceSymbolic logic generally supports the reasoning with propositions, i.e., with statements to be evaluated to true or false. Temporal logic is a special branch of symbolic logic focussing on propositions whose truth values depend on time. That contrasts with the classical logic point of view where the truth value of a repeatedly uttered proposition must always be the same and must neither depend on the modalities of the repetition nor on additional information. Temporal propositions typically contain some (explicit or implicit) reference to time conditions, while classical logic deals with timeless propositions. For instance consider the following examples:A: “The moon is a satellite of the earth”B: “The moon is rising”C: “The moon is setting”Proposition A can be viewed as timeless, since it is true in past, present, and future. In contrast, the propositions B and C have a temporalized aspect and refer to the implicit time condition “now”. Consequently temporal logic applies to time-related universes of discourse where behaviors and courses of events are of interest. As classical logic formulas can characterize static states and properties, temporal logic formulas can describe sequences of state changes and properties of behaviors.Classical logic comprises different logics; several variants of propositional logic, first order predicate logic, etc., exist with different sets of logical operators and inference rules. Likewise some temporal logics were proposed which differ with respect to their formula syntax, semantics, and expressiveness. A temporal logic, however, basically results from an extension of a classical propositional or predicate logic by temporal quantifiers introducing temporalized modalities. Usually, there are at least the two quantifiers s (denoting “always”) and x (denoting “eventually”) and typical formulas are similar to following examples:D:x B “The moon will be rising eventually”E:s x B “The moon will be rising again and again”F:s (B⇒x C) “Moon rise leads to moon setting”The example formula D is true, if the moon is rising now or will be rising in some future point of time. Formula E exemplifies that combinations of temporal quantifiers can denote more complex time conditions, e.g., “always eventually” can correspond to the natural language term “again and again”. Finally, formula F is an example of a “leads-to” pattern describing that always a precondition B will eventually result in a postcondition C.Due to its temporal quantifiers temporal logic is a convenient and appropriate means to reason with time-related propositions. Indeed, classical logic can also handle temporal properties, but the formulas tend to be complicated since points of time have to be explicitly represented in the underlying universe. The formula E may serve as example and underpin the usefulness of temporal logics. The easy-to-read temporal logic formula E corresponds to following predicate logic formula: “For all subjects x a subject y exists such, that – if x is a point of time – y is a point of time equal or later to x and the moon is rising at y”.HistoryTemporal logic is rooted in the field of exact philosophy and is a variant of modal logic. Modal logic deals with propositions which are interpreted with respect to a set of possible worlds. The truth value of propositions depends on the respective world and basically two operators “necessarily” and “possibly” exist which denote that a proposition is true in all possible worlds res. in some possible worlds. Even the ancient Greek philosophy schools of the Megarians, Stoics, and Peripatetics as well as Aristotle used some temporalized form of these modal operators. During the Middle Ages Arabian and European logicians resumed and refined the ancient approaches in order to discern different types of necessity and possibility. In modern times, the interest in symbolic logic grew during the first half of the 20th century, and – with some delay – new modal and temporal logic approaches occurred. First publications date back to the 1940's. In particular, the logicians Prior, Rescher, Kripke, and Scott contributed to the development of modern temporal logic. Kripke presented a formal possible world semantics for modal logics. Prior proposed a temporal interpretation. An ordered set of possible worlds can correspond to a temporal sequence of states. In result, the two basic modal operators “necessarily” and “possibly” become the temporal quantifiers “always” and “eventually”. Based on the linearity of time additional operators like “next” and “until” as well as past operators were introduced. Rescher and Urquhart outlined the history and introduced several major systems of temporal logic in [5]. In 1974, Burstall proposed the application oftemporal logic in computer science for the first time. Pnueli improved this approach in [4], which is regarded as the classic source of temporal logic based program specification and verification.Computer Science ApplicationIn several fields of computer science there is a needs for the formal description of event-discrete processes and the corresponding reasoning. In the main, we have to mention the formal specification and verification of so-called reactive systems, the formalization of real-life processes as well as the semantics of natural language commands to be modeled in artificial intelligence, and finally the handling of dynamic consistency conditions in data base systems.We focus on reactive systems. In particular, Manna and Pnueli recognized in [3] that reactive systems are of growing interest and that temporal logic is well-suited for their formal specification and verification. In contrast to those programs which transform starting states into final results and which may be specified by pre- and postconditions, reactive systems interact with their environment during runtime and the course of interactions and system events is essential. The range of reactive systems is wide and growing. It comprises embedded systems, process control systems, and all types of interactive, concurrent or distributed hard- and software systems. Due to their inherent concurrency, their elaborated fault-tolerance, coordination, and interaction mechanisms distributed systems are rather complex reactive systems and usually need particular design and development tools which support the formal handling of dynamic aspects. Here, temporal logic is profitably applied with respect to following topics:1. Formal specification: Temporal logic formulas serve as precise, concise and binding descriptions of systems andcomponents (e.g., as proposed by Lamport, Manna, and Pnueli in [2] res. [3]).2. Formal verification: The rules of a temporal logic proof calculus are applied to show the correctness of a temporallogic specification with respect to more abstract system specifications (e.g., in [2] and [3]).3. Requirements description: During the early system design the results of the requirements constraining thefunctional system behavior are represented by a set of temporal logic formulas.4. Specification checks: Even if the design specifications use other means than temporal logic (e.g., other formaldescription techniques, see SDL, Estelle, and LOTOS, see also UNITY), temporal logic may be applied additionally in order to describe requirements and plausibility conditions. Meanwhile several approaches exist which support the tool-based checking of formal system specifications with respect to temporal logic conditions (see Model Checking).Linear and Branching TimeUsually, a temporal logic can be classified as so-called linear-time logic which considers behaviors modeled as linear sequences of states. Within one behavior, each state has exactly one future. Additionally, so-called branching-time logics are known. Here, the formulas refer to tree-structured behaviors where a state can have several futures. The behavior-trees can directly correspond to tree models of non-deterministic systems (e.g., synchronization and communication trees, see Calculus of Communicating Systems). A corresponding prominent branching-time logic is CTL (computation tree logic, proposed by Clarke, Emerson, and Sistla in [1]). Its temporal quantifiers directly support the navigation in behavior trees.Non-deterministic systems, however, have not necessarily to be modeled by behavior trees. Likewise, a set of linear state sequences can form a model of a non-deterministic system where each state sequence corresponds to one possible evolution of the system. In comparison with this linear-time approach, branching-time logics additionally provide for notions of potential behaviors since branching-time formulas can describe properties of branches which correspond to subsets of the possible execution sequences while linear-time formulas generally state properties of all possible sequences.VariantsBesides of the mentioned distinctions between temporal propositional and predicate logics and between linear-time and branching-time logics, there exist further variants. Some introduce additional temporal quantifiers like “always in the past”, “sometimes in the past”, “next”, “precedes”, “until”, and “leads-to”. Others extend the time model, e.g., in order to describe time-intervals or real-time quantifications. Furthermore, partial-order temporal logics were proposed which directly refer to partial-order representations of concurrency (see Concurrency Model).ExampleTo exemplify the application of temporal logic for the specification and verification of systems we outline some formula and proof patterns proposed by Lamport in [2] with respect to the Temporal Logic of Actions TLA which is a compact linear-time logic for the reasoning on state-transition systems. He considers the two commonly known classes of properties, invariance and eventuality. Moreover, the correctness of design refinements can be proven with respect to the preservation of properties.An invariance property P is expressed by a formula “s P” where P is a predicate logic formula describing a set of execution states. Inter alia P may specify following typical correctness conditions of a system:1. Partial correctness: P is an implication of the form “system terminated ⇒ correct results computed”.2. Deadlock freedom: P applies to a set of states, the system is not deadlocked.3. Mutual exclusion: P asserts that at most one process is in a critical section.By means of auxiliary history variables all interesting safety properties of a system can be expressed as invariance properties (see Safety Property).The formal proof of invariance properties is supported by a proof rule applying induction on the course of system execution steps. At first, one proves that each initial state implies P. Furthermore, each transition class of the system has to be considered. Each transition has to transform states where P is true into successor states where P is true again. Eventuality properties assert that some events will eventually happen during each execution of a system. The following typical properties can be easily expressed in temporal logic:1. Termination: A formula of the form “x terminated” can assert that each execution leads to a state where the systemis terminated.2. Live service: Each state representing that a service request is pending will be followed by a state the request isserved: “s (requested ⇒x served)”.3. Fair message transfer: If a message is sent often enough over a loose channel, then it is eventually delivered:“(s x sent) ⇒ (x delivered)”.Eventuality properties can express the typical liveness requirements of systems (see Liveness Property).The proof of eventuality properties can be reduced to the proof of a series of transitive leads-to properties of the form “s (P⇒x Q)”. The proof of a single leads-to property is supported by the so-called lattice rule which is based on the existence of a well-founded order. The order asserts that a finite number of execution steps is sufficient to reach a state where Q is true.Systems can be described by formulas on abstract levels as well as on more implementation-near ones. Thus, specifications, refinement steps of a design, and implementations can be represented. That is of great interest, since valid implications correspond to system refinements which are correct in the usual understanding of system developers. Let the formula Spec describe a system S on a more abstract level. A formula Impl describes a correct refinement of S, if the implication formula “Impl ⇒Spec” is provable.References[1] E.M. Clarke, E.A. Emerson, and A.P. Sistla, Automatic Verification of Finite State Concurrent Systems UsingTemporal Logic Specifications, ACM Transactions on Programming Languages and Systems, 8(2): 244-263, 1986 [2] L. Lamport, The Temporal Logic of Actions, ACM Transactions on Programming Languages and Systems,16(3):872-923, 1994[3] Z. Manna and A. Pnueli, The Temporal Logic of Reactive and Concurrent Systems, Springer-Verlag, 1992[4] A. Pnueli, The Temporal Logic of Programs, Proceedings of the 18th IEEE Symposium on Foundations ofComputer Science, pp. 46-57, 1977[5] N. Rescher and A. Urquhart, Temporal Logic, Springer-Verlag, 1971Cross Reference:CTL see Temporal LogicFormal Specification see Temporal LogicFormal Verification see Temporal LogicTLA see Temporal LogicDictionary Terms:Concurrency ModelModel representing the global dynamics of a system which consists of concurrently acting components. Mainly, there are two types of concurrency models. Interleaving models induce a total temporal ordering of all component actions. Thus, the system is assumed to perform a global sequence of actions and the model reduces concurrency to non-determinism. In contrast, partial-order models represent the temporal independence of concurrent events directly. Concurrent events are not comparable with respect to the order of events.Liveness PropertyProperty of a system concerning its dynamics and expressing that the system will eventually show a particular behavior within a finite period of time. Together with safety properties (see Safety Property) liveness properties can be used to characterize the principal functionality of distributed systems.Safety PropertyProperty of a system concerning its dynamics and expressing that the system behavior never injures particular conditions, e.g., never enters forbidden states. Together with liveness properties (see Liveness Property) safety properties can be used to characterize the principal functionality of distributed systems.。
牛顿 自然哲学的数学原理 哲学中的推理规则 英文
牛顿自然哲学的数学原理哲学中的推理规则英文《牛顿自然哲学的数学原理与哲学中的推理规则》Isaac Newton is widely regarded as one of the most influential scientists in history. His groundbreaking work in physics and mathematics laid the foundation for modern science and revolutionized our understanding of the natural world. One of his most significant contributions is the development of the mathematical principles of natural philosophy, which provided a systematic framework for explaining the motion of objects and the behavior of physical systems.Newton's mathematical principles of natural philosophy, as articulated in his seminal work "Philosophiæ Naturalis Principia Mathematica" (Mathematical Principles of Natural Philosophy), laid the groundwork for the development of classical mechanics. Newton's laws of motion, which are based on mathematical principles, provide a quantitative description of the behavior of objects in motion and have been fundamental to the development of modern physics and engineering.In addition to his mathematical principles of natural philosophy, Newton also made important contributions to the field of philosophy, particularly in the area of logic and reasoning. Newton's work on the philosophy of science and his development of empirical methods for testing scientific hypotheses laid the groundwork for the scientific method, which remains the foundation of modern scientific inquiry.The philosophical implications of Newton's work are also manifested in his development of inferential reasoning and the establishment of rules for logical deduction. Newton's emphasis on empirical evidence and his commitment to the use of mathematical and logical reasoning in scientific inquiry has had a lasting impact on the development of philosophical thought and scientific methodology. Overall, Newton's mathematical principles of natural philosophy and his contributions to the development of inferential reasoning and logical deduction have had a profound impact on the development of modern science and philosophy. His work continues to be a source of inspiration and guidance for scientists and philosophers alike, and remains an essential part of the intellectual legacy of the Western tradition.。
有关展览文物的英语作文
The Fascination of Exhibition ArtifactsArtifacts, as tangible remains of the past, carry within them the stories, cultures, and achievements of our ancestors. When these historical treasures are exhibited in museums or galleries, they not only educate but also captivate visitors, offering a glimpse into the rich tapestry of human history.One of the most compelling aspects of exhibition artifacts is their ability to transport us through time. As we stand in front of an ancient pottery vessel, we can almost hear the echoes of the civilization that crafted it. Each artifact is a portal, allowing us to step into the shoes of those who walked the earth centuries ago. This temporal journey is not merely informative; it is emotional and immersive, evoking a sense of wonder and awe.Moreover, artifacts serve as powerful educational tools. They provide concrete evidence of historical events, cultural practices, and technological advancements. For instance, an exhibition showcasing medieval armor not only displays the craftsmanship of the time but also sheds light on the warfare tactics and social hierarchy of the era. Such exhibits enable learners of all ages to grasp complex historical concepts in a tangible and engaging manner.The preservation and exhibition of artifacts also play a crucial role in cultural heritage conservation. By showcasing these treasures, museums and galleries raise awareness about the importance of protecting our shared history. They encourage visitors to appreciate the diversity of human experiences and the value of preserving our cultural roots for future generations.Furthermore, the exhibition of artifacts often sparks curiosity and inspires further exploration. Many visitors leave museums with a newfound interest in a particular historical period or cultural tradition. This curiosity can lead to deeper research, academic pursuits, or even personal projects aimed at uncovering more about the past.In conclusion, exhibition artifacts are not merely objects of historical significance; they are windows to the past, educational tools, cultural ambassadors, and sources of inspiration. They have the power to ignite our imagination, broaden our understanding of the world, and connect us to the generations that walked before us. Visiting an artifact exhibition is not just an educational experience; it is a journey through time that leaves a lasting impression on all who embark on it.。
尊严是永远的赢家英语作文
尊严是永远的赢家英语作文Title: Dignity: The Eternal Victor。
Dignity, often described as the quality of being worthy of honor and respect, stands as an eternal victor amidstthe ebb and flow of time. In a world marked by constant change and uncertainty, dignity remains a steadfast beacon, guiding individuals and societies towards higher ideals and moral fortitude.Firstly, dignity serves as a cornerstone of humanrights and social justice. Regardless of one's background, identity, or circumstances, every individual possesses inherent dignity simply by virtue of being human. This intrinsic worth forms the basis for the recognition and protection of fundamental rights, such as the right to life, liberty, and equality before the law. In advocating for the dignity of all, societies strive towards creating a morejust and equitable world where every person is valued and respected.Moreover, dignity empowers individuals to assert their autonomy and agency in the face of adversity. It is the inner strength that enables individuals to uphold their principles and values, even in the most challenging circumstances. In times of oppression or injustice, dignity serves as a rallying cry for resistance and resilience, inspiring people to stand up for what is right and just. History is replete with examples of individuals and communities who, fueled by their sense of dignity, have mobilized for social change and brought about transformative shifts in society.Furthermore, dignity fosters empathy and compassion, forging connections that transcend differences and unite humanity in solidarity. When we recognize the inherent dignity of others, we are compelled to treat them with kindness, empathy, and respect. This ethos of dignity forms the bedrock of a compassionate society where individuals support and uplift one another, recognizing that each person's dignity is intertwined with their own.Additionally, dignity serves as a bulwark against the corrosive forces of discrimination, prejudice, and dehumanization. By affirming the dignity of every individual, we reject the notion of hierarchy orsuperiority based on arbitrary distinctions such as race, gender, or socioeconomic status. Instead, we embrace the diversity of human experience and celebrate the richness it brings to our collective tapestry. In doing so, we create inclusive spaces where everyone is valued for their unique contributions and perspectives.In conclusion, dignity transcends temporal boundaries, standing as an eternal victor that guides humanity towards a brighter future. As we navigate the complexities of the modern world, let us uphold the dignity of all individuals and strive to build societies founded on principles of justice, compassion, and equality. For in honoring the dignity of others, we ultimately honor our shared humanity and reaffirm our commitment to a world where dignity reigns supreme.。
巴霍巴利王第二部英语生词
巴霍巴利王第二部英语生词The Terminology of Baahubali: The ConclusionIn the epic cinematic saga of Baahubali, the second installment, "Baahubali: The Conclusion," captivated audiences worldwide with its grand storytelling, breathtaking visuals, and a richly woven tapestry of cultural and linguistic elements. As viewers immersed themselves in the captivating narrative, they were introduced to a vast array of terms and concepts that expanded their understanding of the intricate world of Baahubali. This essay delves into the English vocabulary used in the film, exploring the significance and context of these intriguing words and phrases.One of the most prominent terms that emerges in Baahubali: The Conclusion is "Devasena." This name holds immense significance as it refers to the female protagonist, a powerful and resilient warrior princess who plays a pivotal role in the film's events. The name "Devasena" is derived from the Sanskrit words "deva," meaning "deity," and "sena," meaning "army" or "warrior." This combination reflects the character's divine-like qualities and her formidable strength as a warrior.Another key term that resonates throughout the film is "Mahishmati," the grand and ancient kingdom that serves as the primary setting for the Baahubali saga. The word "Mahishmati" is believed to be derived from the Sanskrit word "mahisha," meaning "buffalo," and "mati," meaning "intellect" or "wisdom." This suggests that the kingdom's name may be a reference to the mythological figure of Mahishasura, a powerful buffalo-headed demon who was vanquished by the Hindu goddess Durga.The film's protagonist, Amarendra Baahubali, is a name that is equally captivating. "Amarendra" is a Sanskrit word that combines "amara," meaning "immortal," and "indra," referring to the king of the gods in Hindu mythology. This name conveys the character's exceptional abilities and his elevated status within the narrative. The surname "Baahubali" is a compound word derived from "baahu," meaning "arms" or "strength," and "bali," meaning "power" or "might." This powerful name reflects the protagonist's physical prowess and his commanding presence.Another crucial term in the Baahubali universe is "Kalakeya," the name of the fearsome and merciless tribe that poses a formidable threat to the kingdom of Mahishmati. The word "Kalakeya" is believed to be a reference to the "Kala" demons, a group of powerful and demonic beings in Hindu mythology. The suffix "-keya" suggests a connection to the mythological figure of Kalanemi, a powerfuldemon who was eventually defeated by the avatars of the Hindu god Vishnu.The concept of "Shiva Dhanus," the legendary bow of the Hindu god Shiva, is also central to the events of Baahubali: The Conclusion. The name "Shiva Dhanus" translates to "Shiva's Bow," emphasizing the divine and powerful nature of this iconic weapon. The bow's association with the god Shiva, who is known for his role as the destroyer and transformer in the Hindu trinity, adds a layer of mythological significance to its role in the film's narrative.The term "Rajamata," which appears in the film, refers to the esteemed position of the queen mother or the mother of the ruling monarch. This honorific title reflects the reverence and respect accorded to the female elders within the royal family hierarchy.Additionally, the film introduces the concept of "Aashirwad," a Sanskrit word that means "blessing" or "benediction." This term is used to describe the ceremonial act of bestowing a blessing or granting divine favor upon an individual, often by a respected or revered figure.The intricate web of relationships and power dynamics within the Baahubali narrative is further enhanced by the use of terms like "Rajkumari," meaning "princess," and "Rajkumar," meaning "prince."These designations help to establish the characters' positions within the royal lineage and underscore the importance of bloodline and inheritance in the film's sociopolitical landscape.The film's climactic battle scenes are punctuated by the use of the term "Kshatriya," a designation that refers to the warrior caste in the Hindu social hierarchy. This term highlights the characters' adherence to the warrior code of honor, courage, and loyalty, which is central to the film's thematic exploration of power, duty, and sacrifice.Throughout Baahubali: The Conclusion, the audience is also introduced to the concept of "Dharmashala," a term that describes a rest house or a place of shelter and hospitality, often associated with religious or spiritual establishments. This term reflects the film's engagement with the themes of hospitality, generosity, and the intertwining of temporal and spiritual realms.The linguistic richness of Baahubali: The Conclusion extends beyond the use of Sanskrit-derived terms. The film also incorporates words and phrases from other regional languages, such as "Kakatiya," a reference to the Kakatiya dynasty that once ruled parts of southern India. This linguistic diversity adds to the authenticity and cultural depth of the cinematic world, transporting the audience to a realm that is firmly rooted in the rich tapestry of Indian history andmythology.In conclusion, the English vocabulary employed in Baahubali: The Conclusion serves as a testament to the film's meticulous attention to cultural and linguistic details. From the evocative names of the characters and locations to the conceptual terms that underpin the narrative, these words and phrases collectively contribute to the creation of a cinematic experience that is both visually stunning and intellectually engaging. By delving into the significance and context of these linguistic elements, we can gain a deeper appreciation for the cinematic masterpiece that is Baahubali: The Conclusion, and the profound cultural and mythological resonances that it so skillfully brings to life on the silver screen.。
任务驱动的军事信息服务知识推理研究
收稿日期：2020-03-27修回日期：2020-05-30作者简介：张清辉（1984-），男，山东淄博人，博士，讲师。
研究方向：信息服务，需求工程，虚拟训练。
摘要：根据任务需要敏捷组织信息服务活动，从海量信息资源中提取准确的信息，高效地为各级指挥员提供精准的信息服务，是提升我军信息服务能力的关键所在。
以使命任务、信息服务活动和信息资源为核心概念，建立了军事信息服务本体模型，定义了模型中概念之间的语义关系和时序关系，提出了军事信息服务知识推理方法，为任务驱动的军事信息服务领域知识的推理提供了理论基础。
以封堵河堤溃口突发事件应急处置信息服务模型构建和知识推理实例作为具体测试案例，验证了构建的本体模型和知识推理方法的有效性。
关键词：信息服务，本体，知识推理，军事信息中图分类号：TJ01；TP311文献标识码：ADOI ：10.3969/j.issn.1002-0640.2021.05.012引用格式：张清辉，杨楠，梁政.任务驱动的军事信息服务知识推理研究［J ］.火力与指挥控制，2021，46（5）：64-70.任务驱动的军事信息服务知识推理研究张清辉1，杨楠2，梁政1（1.国防科技大学信息通信学院，西安710106；2.火箭军工程大学，西安710025）Study on Knowledge Reasoning of Task Driven Military Information ServiceZHANG Qing-hui 1，YANG Nan 2，LIANG Zheng 1（rmation and Communication College ，National University of Defense Technology ，Xi ’an 710106，China ；2.Rocket Force University of Engineering ，Xi ’an 710025，China ）Abstract ：Agilely organizing the information service activities according to the requirements oftasks ，extracting accurate information from massive information resources ，and providing accurate information services for each level of commanders efficiently are the keys to improve the information service abilities of our army.Based on the core concepts of missions ，information service activities and information resources ，an ontology model of military information service is established ，the semantic relation and temporal relation between concepts in the model are defined ，and the knowledge reasoning method of military information service is put forward ，which provides the theoretical basis for taskdriven reasoning of military information service domain knowledge.The effectiveness of the ontology model and knowledge reasoning method are verified by the construction of information service model and knowledge reasoning case of an emergency response to block the riverbank breach.Key words ：information service ，ontology ，knowledge reasoning ，military information Citation format ：ZHANG Q H ，YANG N ，LIANG Z.Study on knowledge reasoning of task driven military information service ［J ］.Fire Control &Command Control ，2021，46（5）：64-70.0引言随着我军信息化建设的快速发展，信息采集手段日益丰富，军事信息资源的种类和数量不断增长。
爷爷以前的作文英语怎么说
爷爷以前的作文英语怎么说Title: How to Say "Grandfather's Old Essays" in English。
Introduction:In exploring the intricacies of language translation,we often encounter challenges in accurately conveying the essence of phrases and expressions from one language to another. One such intriguing inquiry is how to articulate "Grandfather's Old Essays" in English. This task necessitates not only linguistic proficiency but also a nuanced understanding of cultural contexts and linguistic subtleties. Delving into this topic, we embark on a journey to unravel the complexities of translation and discover the most apt rendition of this phrase in English.Exploring the Literal Translation:To begin our exploration, let us first dissect the original phrase, "爷爷以前的作文" (Yéyé yǐqián dezuòwén), in Mandarin. "爷爷" (Yéyé) translates to "grandfather," while "以前" (yǐqián) means "before" or "in the past." Finally, "作文" (zuòwén) refers to "essays" or "writings." Thus, a literal translation of the phrase yields "Grandfather's Before Essays." However, this direct translation lacks the elegance and clarity desiredin English expression.Cultural and Linguistic Considerations:Before proceeding further, it is essential to recognize the cultural nuances embedded within the original phrase. In Chinese culture, the term "爷爷" (Yéyé) conveys a sense of reverence and familial respect, reflecting the esteemed role of grandparents within the family hierarchy. Additionally, the phrase "以前" (yǐqián), with its temporal connotations, evokes nostalgia and reminiscence, underscoring the passage of time and the wisdom accrued over the years. These cultural nuances must be carefully preserved in the English rendition to capture the essence of the original phrase.Exploring Equivalent Expressions:In English, conveying the notion of "Grandfather's Old Essays" requires a nuanced approach to encapsulate both the familial reverence and temporal significance embeddedwithin the original phrase. One possible rendition could be "Grandfather's Vintage Writings." The term "vintage" conveys a sense of age and historical significance, akin to the Chinese concept of "以前" (yǐqián), while "writings" maintains the essence of "作文" (zuòwén). However, this rendition may lack the familial warmth and personal connection inherent in the original phrase.Another rendition could be "Grandfather's Legacy Essays." Here, "legacy" imbues the essays with a sense of inheritance and familial heritage, resonating with the reverence accorded to grandparents in Chinese culture. However, this rendition may veer slightly from the temporal connotations of the original phrase.Ultimately, the most suitable rendition may vary depending on the specific context and desired connotations.It is imperative to consider the nuances of both languages and cultures to arrive at an accurate and evocative translation.Conclusion:In our quest to articulate "Grandfather's Old Essays" in English, we have navigated through linguisticintricacies and cultural subtleties to uncover the most apt renditions of this phrase. From "Grandfather's Vintage Writings" to "Grandfather's Legacy Essays," eachtranslation offers a unique perspective on the familial reverence and temporal significance inherent in theoriginal phrase. By embracing the complexities of translation, we gain a deeper appreciation for the rich tapestry of language and culture that unites us across diverse linguistic landscapes.。
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only temporal operator. This answers a question raised by [1] and extends work of [13]. The outline of the paper is as follows: in Sect. 2 we review some basic notions and introduce the EF game for TL; in Sect. 3 we prove the Until hierarchy theorem and its extensions; in Sect. 4 we draw some consequences from the proof of the hierarchy theorem regarding the relationship between TL and first-order logic; in Sect. 5 we use the game in a new way to provide automata-theoretic characterizations for fragments of TL; and in Sect. 6 we make concluding remarks.
An Until Hierarchy for Temporal Logic
Kousha Etessami Thomas Wilke DIMACS Rutgers University Piscataway, NJ 08855 fetessami,wilkeg@ Abstract
1 IntrodBiblioteka ctionTemporal logic is a language for expressing relationships between the order of events occurring over time. A salient feature of the logic is the ability to build nested expressions using “Until”. We establish a strict hierarchy of expressive power for temporal formulas based on Until nesting depth. To do this, we design a new Ehrenfeucht-Fra¨ ıss´ e (EF) game to specifically capture the power of linear temporal logic.
We prove there is a strict hierarchy of expressive power according to the Until depth of linear temporal logic (TL) formulas: for each k, there is a very natural property that is not expressible with k nestings of Until operators, regardless of the number of applications of other operators, but is expressible by a formula with Until depth k + 1. Our proof uses a new Ehrenfeucht-Fra¨ ıss´ e (EF) game designed specifically for TL. These properties can all be expressed in firstorder logic with quantifier depth and size O(log k), and we use them to observe some interesting relationships between TL and first-order expressibility. We then use the EF game in a novel way to effectively characterize (1) the TL properties expressible without Until, as well as (2) those expressible without both Until and Next. By playing the game “on finite automata”, we prove that the automata recognizing languages expressible in each of the two fragments have distinctive structural properties. The characterization for the first fragment was originally proved by Cohen, Perrin, and Pin using sophisticated semigrouptheoretic techniques. They asked whether such a characterization exists for the second fragment. The technique we develop is general and can potentially be applied in other contexts. (See [2, 4] for origins, and, e. g., [7, 16] for more recent use of EF games.) We use our game to show that, for each k 1, there is a property STAIR k+1 that can not be expressed with k ? 1 nestings of Until operators, regardless of the number of applications of other operators. However, STAIRk+1 can be expressed with a formula that has Until depth k. STAIRk is a simple and natural counting property that says: “there is an interval of time in which event a occurs k times but event b does not occur” (where we assume there are other event types possible). H. Kamp [8] proved a long time ago that linear temporal logic is equivalent in expressive power to first-order logic on structures with unary predicates and a (Dedekindcomplete) total ordering (see also, [6, 5]). We use the properties STAIRk to draw some consequences about the relationship between the Until depth required to express a property in temporal logic and the first-order quantifier depth required to express the same property. STAIR k is expressible via a first-order formula of quantifier depth O(log k) using only three variables, as well as a formula of quantifier depth and size O(log k) using 5 variables. Moreover, for all k, STAIRk is expressible with a formula of alternation depth 2. Thus, there are properties whose expression requires exponentially more Until depth than first-order quantifier depth. These results complement some strong succinctness results that can be derived from a proof of Stockmeyer’s [14] combined with other considerations, as will be discussed in section 4. Since TL formulas define regular sets, a natural question that has been asked is whether a given regular set is expressible within TL or within one of its fragments. The work of [11, 9, 8] yields an effective characterization of the finite automata recognizing TL definable sets, while [1] provides an effective characterization for the TL formulas that don’t use the Until operator. Both those characterizations make heavy use of semigroup-theoretic techniques. We use the EF game in a novel way by “playing on finite automata” to simplify the proof of the second result and provide an effective characterization for TL formulas that use “Eventually” as the 1