{"title":"Equivalence of inductive definitions and cyclic proofs under arithmetic","authors":"S. Berardi, M. Tatsuta","doi":"10.1109/LICS.2017.8005114","DOIUrl":"https://doi.org/10.1109/LICS.2017.8005114","url":null,"abstract":"A cyclic proof system, called CLKID-omega, gives us another way of representing inductive definitions and efficient proof search. The 2011 paper by Brotherston and Simpson showed that the provability of CLKID-omega includes the provability of the classical system of Martin-Lof's inductive definitions, called LKID, and conjectured the equivalence. By this year the equivalence has been left an open question. In general, the conjecture was proved to be false in FoSSaCS 2017 paper by Berardi and Tatsuta. However, if we restrict both systems to only the natural number inductive predicate and add Peano arithmetic to both systems, the conjecture was proved to be true in FoSSaCS 2017 paper by Simpson. This paper shows that if we add arithmetic to both systems, they become equivalent, namely, the conjecture holds. The result of this paper includes that of the paper by Simpson as a special case. In order to construct a proof of LKID for a given cyclic proof, this paper shows every bud in the cyclic proof is provable in LKID, by cutting the cyclic proof into subproofs such that in each subproof the conclusion is a companion and the assumptions are buds. The global trace condition gives some induction principle, by using an extension of Podelski-Rybalchenko termination theorem from well-foundedness to induction schema. In order to prove this extension, this paper also shows that infinite Ramsey theorem is formalizable in Peano arithmetic.","PeriodicalId":313950,"journal":{"name":"2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133722902","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}
Małgorzata Biernacka, Dariusz Biernacki, Sergueï Lenglet, Piotr Polesiuk, D. Pous, Alan Schmitt
{"title":"Fully abstract encodings of λ-calculus in HOcore through abstract machines","authors":"Małgorzata Biernacka, Dariusz Biernacki, Sergueï Lenglet, Piotr Polesiuk, D. Pous, Alan Schmitt","doi":"10.1109/LICS.2017.8005118","DOIUrl":"https://doi.org/10.1109/LICS.2017.8005118","url":null,"abstract":"We present fully abstract encodings of the call-byname λ-calculus into HOcore, a minimal higher-order process calculus with no name restriction. We consider several equivalences on the λ-calculus side—normal-form bisimilarity, applicative bisimilarity, and contextual equivalence—that we internalize into abstract machines in order to prove full abstraction.","PeriodicalId":313950,"journal":{"name":"2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116853918","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}
J. Blanchette, Fabian Meier, A. Popescu, Dmitriy Traytel
{"title":"Foundational nonuniform (Co)datatypes for higher-order logic","authors":"J. Blanchette, Fabian Meier, A. Popescu, Dmitriy Traytel","doi":"10.1109/LICS.2017.8005071","DOIUrl":"https://doi.org/10.1109/LICS.2017.8005071","url":null,"abstract":"Nonuniform (or “nested” or “heterogeneous”) datatypes are recursively defined types in which the type arguments vary recursively. They arise in the implementation of finger trees and other efficient functional data structures. We show how to reduce a large class of nonuniform datatypes and codatatypes to uniform types in higher-order logic. We programmed this reduction in the Isabelle/HOL proof assistant, thereby enriching its specification language. Moreover, we derive (co)induction and (co)recursion principles based on a weak variant of parametricity.","PeriodicalId":313950,"journal":{"name":"2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123363234","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 of summation problems for Abelian groups and semigroups","authors":"Faried Abu Zaid, A. Dawar, E. Grädel, Wied Pakusa","doi":"10.1109/LICS.2017.8005082","DOIUrl":"https://doi.org/10.1109/LICS.2017.8005082","url":null,"abstract":"We study the descriptive complexity of summation problems in Abelian groups and semigroups. In general, an input to the summation problem consists of an Abelian semigroup G, explicitly represented by its multiplication table, and a subset X of G. The task is to determine the sum over all elements of X.","PeriodicalId":313950,"journal":{"name":"2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129747108","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":"Bar induction: The good, the bad, and the ugly","authors":"Vincent Rahli, M. Bickford, R. Constable","doi":"10.1109/LICS.2017.8005074","DOIUrl":"https://doi.org/10.1109/LICS.2017.8005074","url":null,"abstract":"We present an extension of the computation system and logic of the Nuprl proof assistant with intuitionistic principles, namely versions of Brouwer's bar induction principle, which is equivalent to transfinite induction. We have substantially extended the formalization of Nuprl's type theory within the Coq proof assistant to show that two such bar induction principles are valid w.r.t. Nuprl's semantics (the Good): one for sequences of numbers that involved only minor changes to the system, and a more general one for sequences of name-free (the Ugly) closed terms that involved adding a limit constructor to Nuprl's term syntax in our model of Nuprl's logic. We have proved that these additions preserve Nuprl's key metatheoretical properties such as consistency. Finally, we show some new insights regarding bar induction, such as the non-truncated version of bar induction on monotone bars is intuitionistically false (the Bad).","PeriodicalId":313950,"journal":{"name":"2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116368935","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":"On shift-invariant maximal filters and hormonal cellular automata","authors":"J. Cervelle, Grégory Lafitte","doi":"10.1109/LICS.2017.8005145","DOIUrl":"https://doi.org/10.1109/LICS.2017.8005145","url":null,"abstract":"This paper deals with the construction of shift-invariant maximal filters on ℤ and their relation to hormonal cellular automata, a generalization of the cellular automata computation model with some information about the global state shared among all the cells. We first design shift-invariant maximal filters in order to define this new model of computation. Starting from different assumptions, we show how to construct such filters, and analyze the computation power of the induced cellular automata computation model.","PeriodicalId":313950,"journal":{"name":"2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117316713","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":"Foundation for a series of efficient simulation algorithms","authors":"Gérard Cécé","doi":"10.1109/LICS.2017.8005069","DOIUrl":"https://doi.org/10.1109/LICS.2017.8005069","url":null,"abstract":"Compute the coarsest simulation preorder included in an initial preorder is used to reduce the resources needed to analyze a given transition system. This technique is applied on many models like Kripke structures, labeled graphs, labeled transition systems or even word and tree automata. Let (Q,→) be a given transition system and ℛ<inf>init</inf> be an initial preorder over Q. Until now, algorithms to compute ℛ<inf>sim</inf>, the coarsest simulation included in ℛ<inf>init</inf>, are either memory efficient or time efficient but not both. In this paper we propose the foundation for a series of efficient simulation algorithms with the introduction of the notion of maximal transitions and the notion of stability of a preorder with respect to a coarser one. As an illustration we solve an open problem by providing the first algorithm with the best published time complexity, O(|P<inf>sim</inf>|.|→|), and a bit space complexity in O(|P<inf>sim</inf>|<sup>2</sup>.log(|P<inf>sim</inf>|)+|Q|.log(|Q|)), with P<inf>sim</inf> the partition induced by ℛ<inf>sim</inf>.","PeriodicalId":313950,"journal":{"name":"2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129860359","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":"On the extension of computable real functions","authors":"M. Hoyrup, W. Gomaa","doi":"10.1109/LICS.2017.8005067","DOIUrl":"https://doi.org/10.1109/LICS.2017.8005067","url":null,"abstract":"We investigate interrelationships among different notions from mathematical analysis, effective topology, and classical computability theory. Our main object of study is the class of computable functions defined over an interval with the boundary being a left-c.e. real number. We investigate necessary and sufficient conditions under which such functions can be computably extended. It turns out that this depends on the behavior of the function near the boundary as well as on the class of left-c.e. real numbers to which the boundary belongs, that is, how it can be constructed. Of particular interest a class of functions is investigated: sawtooth functions constructed from computable enumerations of c.e. sets.","PeriodicalId":313950,"journal":{"name":"2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132414899","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":"Higher-order parity automata","authors":"Paul-André Melliès","doi":"10.1109/LICS.2017.8005077","DOIUrl":"https://doi.org/10.1109/LICS.2017.8005077","url":null,"abstract":"We introduce a notion of higher-order parity automaton which extends to infinitary simply-typed λ-terms the traditional notion of parity tree automaton on infinitary ranked trees. Our main result is that the acceptance of an infinitary λ-term by a higher-order parity automaton A is decidable, whenever the infinitary λ-term is generated by a finite and simply-typed λY-term. The decidability theorem is established by combining ideas coming from linear logic, from denotational semantics and from infinitary rewriting theory.","PeriodicalId":313950,"journal":{"name":"2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114686440","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":"Differentiation in logical form","authors":"A. Edalat, Mehrdad Maleki","doi":"10.1109/LICS.2017.8005143","DOIUrl":"https://doi.org/10.1109/LICS.2017.8005143","url":null,"abstract":"We introduce a logical theory of differentiation for a real-valued function on a finite dimensional real Euclidean space. A real-valued continuous function is represented by a localic approximable mapping between two semi-strong proximity lattices, representing the two stably locally compact Euclidean spaces for the domain and the range of the function. Similarly, the Clarke subgradient, equivalently the L-derivative, of a locally Lipschitz map, which is non-empty, compact and convex valued, is represented by an approximable mapping. Approximable mappings of the latter type form a bounded complete domain isomorphic with the function space of Scott continuous functions of a real variable into the domain of non-empty compact and convex subsets of the finite dimensional Euclidean space partially ordered with reverse inclusion. Corresponding to the notion of a single-tie of a locally Lipschitz function, used to derive the domain-theoretic L-derivative of the function, we introduce the dual notion of a single-knot of approximable mappings which gives rise to Lipschitzian approximable mappings. We then develop the notion of a strong single-tie and that of a strong knot leading to a Stone duality result for locally Lipschitz maps and Lipschitzian approximable mappings. The strong single-knots, in which a Lipschitzian approximable mapping belongs, are employed to define the Lipschitzian derivative of the approximable mapping. The latter is dual to the Clarke subgradient of the corresponding locally Lipschitz map defined domain-theoretically using strong single-ties. A stricter notion of strong single-knots is subsequently developed which captures approximable mappings of continuously differentiable maps providing a gradient Stone duality for these maps. Finally, we derive a calculus for Lipschitzian derivative of approximable mapping for some basic constructors and show that it is dual to the calculus satisfied by the Clarke subgradient.","PeriodicalId":313950,"journal":{"name":"2017 32nd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS)","volume":"189 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133598507","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}