{"title":"Models for name-passing processes: interleaving and causal","authors":"Gian Luca Cattani, Peter Sewell","doi":"10.1109/LICS.2000.855781","DOIUrl":"https://doi.org/10.1109/LICS.2000.855781","url":null,"abstract":"We study syntax-free models for name-passing processes. For interleaving semantics, we identify the indexing structure required of an early labelled transition system to support the usual /spl pi/-calculus operations, defining indexed labelled transition systems. For non-interleaving causal semantics, we define indexed labelled asynchronous transition systems, smoothly generalizing both our interleaving model and the standard asynchronous transition systems model for CCS-like calculi. In each case we relate a denotational semantics to an operational view for bisimulation and causal bisimulation respectively. This is a first step towards a uniform understanding of the semantics and operations of name-passing calculi.","PeriodicalId":300113,"journal":{"name":"Proceedings Fifteenth Annual IEEE Symposium on Logic in Computer Science (Cat. No.99CB36332)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122516009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Imperative programming with dependent types","authors":"H. Xi","doi":"10.1109/LICS.2000.855785","DOIUrl":"https://doi.org/10.1109/LICS.2000.855785","url":null,"abstract":"The article enriches imperative programming with a form of dependent types. We start by explaining some motivations for this enrichment and mentioning some major obstacles that need to be overcome. We then present the design of a source level dependently typed imperative programming language Xanadu, forming both static and dynamic semantics and then establishing the type soundness theorem. We also present realistic examples, which have all been verified in a prototype implementation, in support of the practicality of Xanadu. We claim that the language design of Xanadu is novel and it serves as an informative example that demonstrates a means to combine imperative programming with dependent types.","PeriodicalId":300113,"journal":{"name":"Proceedings Fifteenth Annual IEEE Symposium on Logic in Computer Science (Cat. No.99CB36332)","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127801153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A theory of bisimulation for a fragment of Concurrent ML with local names","authors":"A. Jeffrey, J. Rathke","doi":"10.1109/LICS.2000.855780","DOIUrl":"https://doi.org/10.1109/LICS.2000.855780","url":null,"abstract":"Concurrent ML is an extension of Standard ML with /spl pi/-calculus-like primitives for multi-threaded programming. CML has a reduction semantics, but to date there has been no labelled transitions semantics provided for the entire language. We present a labelled transition semantics for a fragment of CML called /spl mu/vCML which includes features not covered before: dynamically generated local channels and thread identifiers. We show that weak bisimulation for /spl mu/vCML is a congruence, and coincides with barbed bisimulation congruence. We also provide a variant of D. Sangiorgi's (1993) normal bisimulation for /spl mu/vCML, and show that this too coincides with bisimulation.","PeriodicalId":300113,"journal":{"name":"Proceedings Fifteenth Annual IEEE Symposium on Logic in Computer Science (Cat. No.99CB36332)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114187759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Logic, complexity, and games","authors":"Ronald Fagin","doi":"10.1109/LICS.2000.855750","DOIUrl":"https://doi.org/10.1109/LICS.2000.855750","url":null,"abstract":"In this talk, I will discuss an approach to the P = NP question via the correspondence between logic and complexity. The focus will be on the possible use of Ehrenfeucht-Fraisse games.","PeriodicalId":300113,"journal":{"name":"Proceedings Fifteenth Annual IEEE Symposium on Logic in Computer Science (Cat. No.99CB36332)","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115931667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A model for impredicative type systems, universes, intersection types and subtyping","authors":"Alexandre Miquel","doi":"10.1109/LICS.2000.855752","DOIUrl":"https://doi.org/10.1109/LICS.2000.855752","url":null,"abstract":"We introduce a novel model based on coherence spaces for interpreting large impredicative type systems such as the Extended Calculus of Constructions (ECC). Moreover we show that this model is well-suited for interpreting intersection types and subtyping too, and we illustrate this by interpreting a variant of ECC with an additional intersection type binder. Furthermore, we propose a general method for interpreting the impredicative level in a non-syntactical way, by allowing the model to be parametrized by an arbitrarily large coherence space in order to interpret inhabitants of impredicative types. As an application, we show that uncountable types such as the type of real numbers or Zermelo-Frankel sets can safely be axiomatized on the impredicative level of, say, ECC, without harm for consistency.","PeriodicalId":300113,"journal":{"name":"Proceedings Fifteenth Annual IEEE Symposium on Logic in Computer Science (Cat. No.99CB36332)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121732228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Concurrent omega-regular games","authors":"L. D. Alfaro, T. Henzinger","doi":"10.1109/LICS.2000.855763","DOIUrl":"https://doi.org/10.1109/LICS.2000.855763","url":null,"abstract":"We consider two-player games which are played on a finite state space for an infinite number of rounds. The games are concurrent, that is, in each round, the two players choose their moves independently and simultaneously; the current state and the two moves determine a successor state. We consider omega-regular winning conditions on the resulting infinite state sequence. To model the independent choice of moves, both players are allowed to use randomization for selecting their moves. This gives rise to the following qualitative modes of winning, which can be studied without numerical considerations concerning probabilities: sure-win (player 1 can ensure winning with certainty); almost-sure-win (player 1 can ensure winning with probability 1); limit-win (player 1 can ensure winning with probability arbitrarily close to 1); bounded-win (player 1 can ensure winning with probability bounded away from 0); positive-win (player 1 can ensure winning with positive probability); and exist-win (player 1 can ensure that at least one possible outcome of the game satisfies the winning condition). We provide algorithms for computing the sets of winning states for each of these winning modes. In particular, we solve concurrent Rabin-chain games in n/sup O/(m) time, where n is the size of the game structure and m is the number of pairs in the Rabin-chain condition. While this complexity is in line with traditional turn-based games, our algorithms are considerably more involved. This is because concurrent games violate two of the most basic properties of turn-based games: concurrent games are not determined, but rather exhibit a more general duality property which involves multiple modes of winning; and winning strategies for concurrent games may require infinite memory.","PeriodicalId":300113,"journal":{"name":"Proceedings Fifteenth Annual IEEE Symposium on Logic in Computer Science (Cat. No.99CB36332)","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131993900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Definability and compression","authors":"F. Afrati, Hans Leiss, M. D. Rougemont","doi":"10.1109/LICS.2000.855756","DOIUrl":"https://doi.org/10.1109/LICS.2000.855756","url":null,"abstract":"A compression algorithm takes a finite structure of a class K as input and produces a finite structure of a different class K' as output. Given a property P on the class K defined in a logic /spl Lscr/, we study the definability of property P on the class K'. We consider two compression schemas on unary ordered structures (words), compression by runlength encoding and the classical Lempel-Ziv. First-order properties of strings are first-order on runlength compressed strings, but this fails for images, i.e. 2-dimensional strings. We present simple first-order properties of strings which are not first-order definable on strings compressed with the Lempel-Ziv compression schema. We show that all properties of strings that are first-order definable on strings are definable on Lempel-Ziv compressed strings in FO(TC), the extension of first-order logic with the transitive closure operator. We define a subclass /spl Fscr/ of the first-order properties of strings such that if L is defined by a property in /spl Fscr/, it is also first-order definable on the Lempel-Ziv compressed strings. Monadic second-order properties of strings are dyadic second order definable on Lempel-Ziv compressed strings.","PeriodicalId":300113,"journal":{"name":"Proceedings Fifteenth Annual IEEE Symposium on Logic in Computer Science (Cat. No.99CB36332)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115877081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The curry-howard correspondence in set theory","authors":"J. Krivine","doi":"10.1109/LICS.2000.855779","DOIUrl":"https://doi.org/10.1109/LICS.2000.855779","url":null,"abstract":"This talk presents a system of typed lambda-calculus for the Zermelo-Frankel set theory, in the framework of classical logic [10]. The Curry-Howard correspondence between proofs and programs was originally discovered with the system of simple types, which uses the intuitionistic propositional calculus, with the only connective. It was extended to second order intuitionistic logic, in 1970, by J.-Y. Girard [4], under the name of system F for which he proved the normalization property .The relation with programming languages was made by Reynolds [13].More recently, in 1990, the Curry-Howard correspondence was extended to classical logic, following Felleisen and Griffin [6] who discovered that the law of Peirce corresponds to control instructions in functional programming languages. It is interesting to notice that, as early as 1972, Clint and Hoare [1] had made an analogous remark for the law of excluded middle and controlled jump instructions in imperative languages.There are now many type systems, which are based on classical logic, among the best known are the system LC of J.-Y. Girard [5] and the e µ-calculus of M. Parigot [12]. We use a system closely related to the latter, called the e c calculus [8, 9]. Both systems use classical second order logic and have the normalization property.In order to extend the Curry -Howard correspondence to classical Zermelo-Frankel set theory, we give realizability models, which are built recursively like in the well-known construction of forcing. We show that each axiom of ZF is then realized; we obtain in this way a type s stem in which set-theoretic proofs are formalizable and give rise to programs, which are e -terms with control instructions. In this system, the normalization property is ?essentially true? in the sense that we get correct computations on data types. Of course, not every typable term is normalizable since, for example, Y has the type of the foundation axiom. These realizability models differ deeply from forcing models and pose several interesting problems. In particular, they do not seem to be end extensions of the original model of ZFC. In addition, it is likely that the negation of the axiom of choice is realized in them.","PeriodicalId":300113,"journal":{"name":"Proceedings Fifteenth Annual IEEE Symposium on Logic in Computer Science (Cat. No.99CB36332)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121673548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Diego Calvanese, Giuseppe De Giacomo, M. Lenzerini, Moshe Y. Vardi
{"title":"View-based query processing and constraint satisfaction","authors":"Diego Calvanese, Giuseppe De Giacomo, M. Lenzerini, Moshe Y. Vardi","doi":"10.1109/LICS.2000.855784","DOIUrl":"https://doi.org/10.1109/LICS.2000.855784","url":null,"abstract":"View-based query processing requires answering a query posed to a database only on the basis of the information on a set of views, which are again queries over the same database. This problem is relevant in many aspects of database management, and has been addressed by means of two basic approaches: query rewriting and query answering. In the former approach, one tries to compute a rewriting of the query in terms of the views, whereas in the latter, one aims at directly answering the query based on the view extensions. We study view based query processing for the case of regular-path queries, which are the basic querying mechanisms for the emergent field of semistructured data. Based on recent results, we first show that a rewriting is in general a co-NP function wrt to the size of view extensions. Hence, the problem arises of characterizing which instances of the problem admit a rewriting that is PTIME. A second contribution of the work is to establish a tight connection between view based query answering and constraint satisfaction problems, which allows us to show that the above characterization is going to be difficult. As a third contribution, we present two methods for computing PTIME rewritings of specific forms. The first method, which is based on the established connection with constraint satisfaction problems, gives us rewritings expressed in Datalog with a fixed number of variables. The second method, based on automata-theoretic techniques, gives us rewritings that are formulated as unions of conjunctive regular-path queries with a fixed number of variables.","PeriodicalId":300113,"journal":{"name":"Proceedings Fifteenth Annual IEEE Symposium on Logic in Computer Science (Cat. No.99CB36332)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125545502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"How to optimize proof-search in modal logics: a new way of proving redundancy criteria for sequent calculi","authors":"A. Voronkov","doi":"10.1109/LICS.2000.855787","DOIUrl":"https://doi.org/10.1109/LICS.2000.855787","url":null,"abstract":"We present a bottom-up decision procedure for propositional modal logic K based on the inverse method. The procedure is based on the \"inverted\" version of a sequent calculus. To restrict the search space; we prove a number of redundancy criteria for derivations in the sequent calculus. We introduce a new technique of proving redundancy criteria, based on the analysis of tableau-based derivations in K. Moreover another new technique is used to prove completeness of proof-search with a strong notion of subsumption. This technique is based on so-called traces. A new formalization of the inverse method in the form of a path calculus considerably simplifies all proofs as compared to the previously published presentations of the inverse method. Experimental results reported elsewhere demonstrate that our method is competitive with many state-of-the-art implementations of K.","PeriodicalId":300113,"journal":{"name":"Proceedings Fifteenth Annual IEEE Symposium on Logic in Computer Science (Cat. No.99CB36332)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126971706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}