Proceedings. 14th Symposium on Logic in Computer Science (Cat. No. PR00158)

5-5 July 1999

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  • Proceedings. 14th Symposium on Logic in Computer Science (Cat. No. PR00158)

    Publication Year: 1999
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    Freely Available from IEEE
  • Author index

    Publication Year: 1999, Page(s):477 - 478
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    Freely Available from IEEE
  • Weak bisimulation and open maps

    Publication Year: 1999, Page(s):67 - 76
    Cited by:  Papers (6)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (236 KB)

    A systematic treatment of weak bisimulation and observational congruence on presheaf models is presented. The theory is developed with respect to a “hiding” functor from a category of paths to observable paths. Via a view of processes as bundles, we are able to account for weak morphisms (roughly only required to preserve observable paths) and to derive a saturation monad (on the categ... View full abstract»

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  • Towards a theory of bisimulation for local names

    Publication Year: 1999, Page(s):56 - 66
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (168 KB)

    A.M. Pitts and I.D.B. Stark (1998) have proposed the v-calculus as a language for investigating the interaction of unique name generation and higher-order functions. They developed a sound model based on logical relations, but left completeness as an open problem. In this paper, we develop a complete model based on bisimulation for a labelled transition system semantics. We show that bisimulation ... View full abstract»

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  • Guarded fixed point logic

    Publication Year: 1999, Page(s):45 - 54
    Cited by:  Papers (16)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (240 KB)

    Guarded fixed point logics are obtained by adding least and greatest fixed points to the guarded fragments of first-order logic that were recently introduced by H. Andreka et al. (1998). Guarded fixed point logics can also be viewed as the natural common extensions of the modal p-calculus and the guarded fragments. We prove that the satisfiability problems for guarded fixed point logics are decida... View full abstract»

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  • Some computational properties of intersection types

    Publication Year: 1999, Page(s):109 - 118
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (184 KB)

    This paper presents a new method for comparing computation-properties of λ-terms typeable with intersection types with respect to terms typeable with Curry types. In particular, strong normalization and λ-definability are investigated. A translation is introduced from intersection typing derivations to Curry typeable terms; the main feature of the proposed technique is that the trans... View full abstract»

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  • Parametric quantitative temporal reasoning

    Publication Year: 1999, Page(s):336 - 343
    Cited by:  Papers (20)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (264 KB)

    We define Parameterized Real-Time Computation Tree Logic (PRTCTL), which allows quantitative temporal specifications to be parameterized over the natural numbers. Parameterized quantitative specifications are quantitative specifications in which concrete timing information has been abstracted away. Such abstraction allows designers to specify quantitative restrictions on the temporal ordering of e... View full abstract»

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  • First-order logic vs. fixed-point logic in finite set theory

    Publication Year: 1999, Page(s):275 - 284
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (240 KB)

    The ordered conjecture states that least fixed-point logic LFP is strictly more expressive than first-order logic FO on every infinite class of ordered finite structures. It has been established that either way of settling this conjecture would resolve open problems in complexity theory. In fact, this holds true even for the particular instance of the ordered conjecture on the class of BIT-structu... View full abstract»

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  • Logics with aggregate operators

    Publication Year: 1999, Page(s):35 - 44
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (372 KB)

    We study adding aggregate operators, such as summing up elements of a column of a relation, to logics with counting mechanisms. The primary motivation comes from database applications, where aggregate operators are present in all real life query languages. Unlike other features of query languages, aggregates are not adequately captured by the existing logical formalisms. Consequently, all previous... View full abstract»

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  • Full abstraction and universality via realisability

    Publication Year: 1999, Page(s):174 - 182
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (224 KB)

    We construct fully abstract realisability models of PCF. In particular, we prove a variant of the Longley-Phoa Conjecture by showing that the realisability model over an untyped λ-calculus with arithmetic is fully abstract for PCF. Further we consider the extension of our results to a general sequential functional programming language SFPL giving rise to universal realisability models for S... View full abstract»

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  • Semantical analysis of higher-order abstract syntax

    Publication Year: 1999, Page(s):204 - 213
    Cited by:  Papers (22)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (204 KB)

    A functor category semantics for higher-order abstract syntax is proposed with the following aims: relating higher order and first order syntax, justifying induction principles, suggesting new logical principles to reason about higher-order syntax View full abstract»

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  • On the expressive power of CTL

    Publication Year: 1999, Page(s):360 - 368
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (180 KB)

    We show that the expressive power of the branching time logic CTL coincides with that of the class of bisimulation invariant properties expressible in so-called monadic path logic: monadic second order logic in which set quantification is restricted to paths. In order to prove this result, we first prove a new composition theorem for trees. This approach is adapted from the approach of Hafer and T... View full abstract»

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  • Counting and addition cannot express deterministic transitive closure

    Publication Year: 1999, Page(s):326 - 334
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (196 KB)

    An important open question in complexity theory is whether the circuit complexity class TC0 is (strictly) weaker than LOGSPACE. This paper considers this question from the viewpoint of descriptive complexity theory. TC0 can be characterized as the class of queries expressible by the logic FOC(<, +, ×), which is first-order logic augmented by counting quantifiers on o... View full abstract»

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  • Weak bounded arithmetic, the Diffie-Hellman problem and Constable's Class K

    Publication Year: 1999, Page(s):268 - 274
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (288 KB)

    The bounded arithmetic theory C20, which is closely related to the complexity class DLogTime-uniform TC0, is extended by a function symbol and axioms for integer division, which is not known to be in DLogTime-uniform TC0. About this extended theory C20[div], two main results are proved: (1). The Z1b-definable f... View full abstract»

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  • Pattern matching as cut elimination

    Publication Year: 1999, Page(s):98 - 108
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (232 KB)

    We present a typed pattern calculus with explicit pattern matching and explicit substitutions, where both the typing rules and the reduction rules are modeled on the same logical proof system, namely Gentzen sequent calculus for minimal logic. Our calculus is inspired by the Curry-Howard isomorphism, in the sense that types, both for patterns and terms, correspond to propositions, terms correspond... View full abstract»

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  • A fully abstract game semantics for finite nondeterminism

    Publication Year: 1999, Page(s):422 - 430
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (180 KB)

    A game semantics of finite nondeterminism is proposed. In this model, a strategy may make a choice between different moves in a given situation; moreover, strategies carry extra information about their possible divergent behaviour. A Cartesian closed category is built and a model of a simple, higher-order nondeterministic imperative language is given. This model is shown to be fully abstract, with... View full abstract»

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  • The two-variable guarded fragment with transitive relations

    Publication Year: 1999, Page(s):24 - 34
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (400 KB)

    We consider the restriction of the guarded fragment to the two-variable case where, in addition, binary relations may be specified as transitive. We show that (i) this very restricted form of the guarded fragment without equality is undecidable and that (ii) when allowing non-unary relations to occur only in guards, the logic becomes decidable. The latter subclass of the guarded fragments the one ... View full abstract»

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  • Abstract syntax and variable binding

    Publication Year: 1999, Page(s):193 - 202
    Cited by:  Papers (41)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (240 KB)

    We develop a theory of abstract syntax with variable binding. To every binding signature we associate a category of models consisting of variable sets endowed with compatible algebra and substitution structures. The syntax generated by the signature is the initial model. This gives a notion of initial algebra semantics encompassing the traditional one; besides compositionality, it automatically ve... View full abstract»

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  • On the verification of broadcast protocols

    Publication Year: 1999, Page(s):352 - 359
    Cited by:  Papers (43)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (172 KB)

    We analyze the model-checking problems for safety and liveness properties in parameterized broadcast protocols. We show that the procedure suggested previously for safety properties may not terminate, whereas termination is guaranteed for the procedure based on upward closed sets. We show that the model-checking problem for liveness properties is undecidable. In fact, even the problem of deciding ... View full abstract»

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  • A superposition decision procedure for the guarded fragment with equality

    Publication Year: 1999, Page(s):295 - 303
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (280 KB)

    We give a new decision procedure for the guarded fragment with equality. The procedure is based on resolution with superposition. We argue that this method will be more useful in practice than methods based on the enumeration of certain finite structures. It is surprising to see that one does not need any sophisticated simplification and redundancy elimination method to make superposition terminat... View full abstract»

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  • Paramodulation with non-monotonic orderings

    Publication Year: 1999, Page(s):225 - 233
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (164 KB)

    All current completeness results for ordered paramodulation require the term ordering > to be well-founded, monotonic and total(izable) on ground terms. Here we introduce a new proof technique where the only properties required for > are well foundedness and the subterm property: The technique is a relatively simple and elegant application of some fundamental results on the termination and c... View full abstract»

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  • Reasoning about common knowledge with infinitely many agents

    Publication Year: 1999, Page(s):384 - 393
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (216 KB)

    Complete axiomatizations and exponential-time decision procedures are provided for reasoning about knowledge and common knowledge when there are infinitely many agents. The results show that reasoning about knowledge and common knowledge with infinitely many agents is no harder than when there are finitely many agents, provided that we can check the cardinality of certain set differences G G' wher... View full abstract»

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  • Logics with counting, auxiliary relations, and lower bounds for invariant queries

    Publication Year: 1999, Page(s):316 - 325
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (340 KB)

    We study the expressive power of counting logics in the presence of auxiliary relations such as orders and pre-orders. The simplest such logic, first-order with counting, captures the complexity class TC0 over ordered structures. We also consider first-order logic with arbitrary unary quantifiers, and infinitary extensions. The main result of the paper is that all the counting logics a... View full abstract»

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  • Cartesian closed double categories, their lambda-notation, and the pi-calculus

    Publication Year: 1999, Page(s):246 - 265
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (472 KB)

    We introduce the notion of cartesian closed double category to provide mobile calculi for communicating systems with specific semantic models: One dimension is dedicated to compose systems and the other to compose their computations and their observations. Also, inspired by the connection between simply typed λ-calculus and cartesian closed categories, we define a new typed framework, calle... View full abstract»

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  • Correctness of multiplicative proof nets is linear

    Publication Year: 1999, Page(s):454 - 463
    Cited by:  Papers (9)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (216 KB)

    We reformulate Danos contractibility criterion in terms of a sort of unification. As for term unification, a direct implementation of the unification criterion leads to a quasi-linear algorithm. Linearity is obtained after observing that the disjoint-set union-find at the core of the unification criterion is a special case of union-find with a real linear time solution View full abstract»

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