{"title":"On Noetherian Spaces","authors":"J. Goubault-Larrecq","doi":"10.1109/LICS.2007.34","DOIUrl":"https://doi.org/10.1109/LICS.2007.34","url":null,"abstract":"A topological space is Noetherian iff every open is compact. Our starting point is that this notion generalizes that of well-quasi order, in the sense that an Alexandroff-discrete space is Noetherian iff its specialization quasi-ordering is well. For more general spaces, this opens the way to verifying infinite transition systems based on non-well quasi ordered sets, but where the preimage operator satisfies an additional continuity assumption. The technical development rests heavily on techniques arising from topology and domain theory, including sobriety and the de Groot dual of a stably compact space. We show that the category Nthr of Noetherian spaces is finitely complete and finitely cocomplete. Finally, we note that if X is a Noetherian space, then the set of all (even infinite) subsets of X is again Noetherian, a result that fails for well-quasi orders.","PeriodicalId":137827,"journal":{"name":"22nd Annual IEEE Symposium on Logic in Computer Science (LICS 2007)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123607036","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":"Relational Parametricity for Computational Effects","authors":"Rasmus Ejlers Møgelberg, A. Simpson","doi":"10.2168/LMCS-5(3:7)2009","DOIUrl":"https://doi.org/10.2168/LMCS-5(3:7)2009","url":null,"abstract":"According to Strachey, a polymorphic program is parametric if it applies a uniform algorithm independently of the type instantiations at which it is applied. The notion of relational parametricity, introduced by Reynolds, is one possible mathematical formulation of this idea. Relational parametricity provides a powerful tool for establishing data abstraction properties, proving equivalences of datatypes, and establishing equalities of programs. Such properties have been well studied in a pure functional setting. Many programs, however, exhibit computational effects. In this paper, we develop a framework for extending the notion of relational parametricity to languages with effects.","PeriodicalId":137827,"journal":{"name":"22nd Annual IEEE Symposium on Logic in Computer Science (LICS 2007)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127850574","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}
Yuxin Deng, R. V. Glabbeek, M. Hennessy, Carroll Morgan
{"title":"Characterising Testing Preorders for Finite Probabilistic Processes","authors":"Yuxin Deng, R. V. Glabbeek, M. Hennessy, Carroll Morgan","doi":"10.2168/LMCS-4(4:4)2008","DOIUrl":"https://doi.org/10.2168/LMCS-4(4:4)2008","url":null,"abstract":"In 1992 Wang & Larsen extended the may- and must preorders of De Nicola and Hennessy to processes featuring probabilistic as well as nondeterministic choice. They concluded with two problems that have remained open throughout the years, namely to find complete axiomatisations and alternative characterisations for these preorders. This paper solves both problems for finite processes with silent moves. It characterises the may preorder in terms of simulation, and the must preorder in terms of failure simulation. It also gives a characterisation of both preorders using a modal logic. Finally it axiomatises both preorders over a probabilistic version of CSP.","PeriodicalId":137827,"journal":{"name":"22nd Annual IEEE Symposium on Logic in Computer Science (LICS 2007)","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126429320","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":"Separating DAG-Like and Tree-Like Proof Systems","authors":"Phuong Nguyen","doi":"10.1109/LICS.2007.42","DOIUrl":"https://doi.org/10.1109/LICS.2007.42","url":null,"abstract":"We show that tree-like (Gentzen's calculus) PK where all cut formulas have depth at most a constant d does not simulate cut-free PK. Generally, we exhibit a family of sequents that have polynomial size cut-free proofs but requires superpolynomial tree-like proofs even when the cut rule is allowed on a class of cut-formulas that satisfies some plausible hardness assumption. This gives (in some cases, conditional) negative answers to several questions from a recent work of Maciel and Pitassi (LICS 2006). Our technique is inspired by the technique from Maciel and Pitassi. While the sequents used in earlier work are derived from the Pigeonhole principle, here we generalize Statman's sequents. This gives the desired separation, and at the same time provides stronger results in some cases.","PeriodicalId":137827,"journal":{"name":"22nd Annual IEEE Symposium on Logic in Computer Science (LICS 2007)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126384396","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":"Infinite State AMC-Model Checking for Cryptographic Protocols","authors":"D. Kähler, Ralf Küsters, Tomasz Truderung","doi":"10.1109/LICS.2007.26","DOIUrl":"https://doi.org/10.1109/LICS.2007.26","url":null,"abstract":"Only very little is known about the automatic analysis of cryptographic protocols for game-theoretic security properties. In this paper, we therefore study decidability and complexity of the model checking problem for AMC-formulas over infinite state concurrent game structures induced by cryptographic protocols and the Dolev-Yao intruder. We show that the problem is NEXPTIME-complete when making reasonable assumptions about protocols and for an expressive fragment of AMC, which contains, for example, all properties formulated by Kremer and Raskin in fair ATL for contract-signing and non-repudiation protocols. We also prove that our assumptions on protocols are necessary to obtain decidability, unless other restrictions are imposed on protocols.","PeriodicalId":137827,"journal":{"name":"22nd Annual IEEE Symposium on Logic in Computer Science (LICS 2007)","volume":"10 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128227592","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 Complete Axiomatization of Knowledge and Cryptography","authors":"Mika Cohen, M. Dam","doi":"10.1109/LICS.2007.4","DOIUrl":"https://doi.org/10.1109/LICS.2007.4","url":null,"abstract":"The combination of first-order epistemic logic with formal cryptography offers a potentially powerful framework for security protocol verification. In this paper, cryptography is modelled using private constants and one-way computable operations, as in the applied Pi-calculus. To give the concept of knowledge a computational justification, we propose a generalized Kripke semantics that uses permutations on the underlying domain of cryptographic messages to reflect agents' limited resources. This interpretation links the logic tightly to static equivalence, another important concept of knowledge that has recently been examined in the security protocol literature, and for which there are strong computational soundness results. We exhibit an axiomatization which is sound and complete relative to the underlying theory of terms, and to an omega-rule for quantifiers. Besides standard axioms and rules, the axiomatization includes novel axioms for the interaction between knowledge and cryptography. As protocol examples we use mixes, a Crowds-style protocol, and electronic payments. Furthermore, we provide embedding results for BAN and SVO.","PeriodicalId":137827,"journal":{"name":"22nd Annual IEEE Symposium on Logic in Computer Science (LICS 2007)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128245542","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 Cost of Punctuality","authors":"P. Bouyer, N. Markey, J. Ouaknine, J. Worrell","doi":"10.1109/LICS.2007.49","DOIUrl":"https://doi.org/10.1109/LICS.2007.49","url":null,"abstract":"In an influential paper titled \"The benefits of relaxing punctuality\" [2], Alur, Feder, and Henzinger introduced Metric Interval Temporal Logic (MITL) as a fragment of the real-time logic metric temporal logic (MTL) in which exact or punctual timing constraints are banned. Their main result showed that model checking and satisfiability for MITL are both EXPSPACE-Complete. Until recently, it was widely believed that admitting even the simplest punctual specifications in any linear-time temporal logic would automatically lead to undecidability. Although this was recently disproved, until now no punctual fragment of MTL was known to have even primitive recursive complexity (with certain decidable fragments having provably non-primitive recursive complexity). In this paper we identify a \"co-flat' subset of MTL that is capable of expressing a large class of punctual specifications and for which model checking (although not satisfiability) has no complexity cost over MITL. Our logic is moreover qualitatively different from MITL in that it can express properties that are not timed-regular. Correspondingly, our decision procedures do not involve translating formulas into finite-state automata, but rather into certain kinds of reversal-bounded Turing machines. Using this translation we show that the model checking problem for our logic is EXPSPACE-Complete.","PeriodicalId":137827,"journal":{"name":"22nd Annual IEEE Symposium on Logic in Computer Science (LICS 2007)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134271896","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 Contraction Method to Decide MSO Theories of Deterministic Trees","authors":"A. Montanari, G. Puppis","doi":"10.1109/LICS.2007.6","DOIUrl":"https://doi.org/10.1109/LICS.2007.6","url":null,"abstract":"In this paper we generalize the contraction method, originally proposed by Elgot and Rabin and later extended by Carton and Thomas, from labeled linear orderings to colored deterministic trees. The method we propose rests on a suitable notion of indistinguishability of trees with respect to tree automata that allows us to reduce a number of instances of the acceptance problem for tree automata to decidable instances involving regular trees. We prove that such a method works effectively for a large class of trees, which is closed under noticeable operations and includes all the deterministic trees of the Caucal hierarchy obtained via unfoldings and inverse finite mappings as well as several trees outside such a hierarchy.","PeriodicalId":137827,"journal":{"name":"22nd Annual IEEE Symposium on Logic in Computer Science (LICS 2007)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124935305","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}
R. Alur, M. Arenas, P. Barceló, K. Etessami, N. Immerman, L. Libkin
{"title":"First-Order and Temporal Logics for Nested Words","authors":"R. Alur, M. Arenas, P. Barceló, K. Etessami, N. Immerman, L. Libkin","doi":"10.2168/LMCS-4(4:11)2008","DOIUrl":"https://doi.org/10.2168/LMCS-4(4:11)2008","url":null,"abstract":"Nested words are a structured model of execution paths in procedural programs, reflecting their call and return nesting structure. Finite nested words also capture the structure of parse trees and other tree-structured data, such as XML. We provide new temporal logics for finite and infinite nested words, which are natural extensions of LTL, and prove that these logics are first-order expressively- complete. One of them is based on adding a \"within\" modality, evaluating a formula on a subword, to a logic CaRet previously studied in the context of verifying properties of recursive state machines. The other logic is based on the notion of a summary path that combines the linear and nesting structures. For that logic, both model-checking and satisfiability are shown to be EXPTIME-complete. Finally, we prove that first-order logic over nested words has the three-variable property, and we present a temporal logic for nested words which is complete for the two- variable fragment of first-order.","PeriodicalId":137827,"journal":{"name":"22nd Annual IEEE Symposium on Logic in Computer Science (LICS 2007)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131441244","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":"Two-way unary temporal logic over trees","authors":"M. Bojanczyk","doi":"10.2168/LMCS-5(3:5)2009","DOIUrl":"https://doi.org/10.2168/LMCS-5(3:5)2009","url":null,"abstract":"We consider a temporal logic EF + F-1 for unranked, unordered finite trees. The logic has two operators: EFphi , which says \"in some proper descendant phi holds\", and F-1phi , which says \"in some proper ancestor phi holds\". We present an algorithm for deciding if a regular language of unranked finite trees can be expressed in EF + F-1. The algorithm uses a characterization expressed in terms of forest algebras.","PeriodicalId":137827,"journal":{"name":"22nd Annual IEEE Symposium on Logic in Computer Science (LICS 2007)","volume":"342 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120881712","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}