{"title":"A Formal Study of Boolean Games with Random Formulas as Payoff Functions","authors":"Érik Martin-Dorel, S. Soloviev","doi":"10.4230/LIPIcs.TYPES.2016.14","DOIUrl":"https://doi.org/10.4230/LIPIcs.TYPES.2016.14","url":null,"abstract":"In this paper, we present a probabilistic analysis of Boolean games. We consider the class of Boolean games where payoff functions are given by random Boolean formulas. This permits to study certain properties of this class in its totality, such as the probability of existence of a winning strategy, including its asymptotic behaviour. With the help of the Coq proof assistant, we develop a Coq library of Boolean games, to provide a formal proof of our results, and a basis for further developments. 2012 ACM Subject Classification Theory of computation → Higher order logic, Theory of computation → Algorithmic game theory, Mathematics of computing → Stochastic processes","PeriodicalId":131421,"journal":{"name":"Types for Proofs and Programs","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130911262","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":"Realizability at Work: Separating Two Constructive Notions of Finiteness","authors":"M. Bezem, T. Coquand, Keiko Nakata, Erik Parmann","doi":"10.4230/LIPIcs.TYPES.2016.6","DOIUrl":"https://doi.org/10.4230/LIPIcs.TYPES.2016.6","url":null,"abstract":"We elaborate in detail a realizability model for Martin-Löf dependent type theory with the purpose to analyze a subtle distinction between two constructive notions of finiteness of a set A. The two notions are: (1) A is Noetherian: the empty list can be constructed from lists over A containing duplicates by a certain inductive shortening process; (2) A is streamless: every enumeration of A contains a duplicate. 2012 ACM Subject Classification Theory of computation → Type theory, Theory of computation → Constructive mathematics","PeriodicalId":131421,"journal":{"name":"Types for Proofs and Programs","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128673477","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}
T. Petrucciani, Giuseppe Castagna, D. Ancona, E. Zucca
{"title":"Semantic subtyping for non-strict languages","authors":"T. Petrucciani, Giuseppe Castagna, D. Ancona, E. Zucca","doi":"10.4230/LIPIcs.TYPES.2018.4","DOIUrl":"https://doi.org/10.4230/LIPIcs.TYPES.2018.4","url":null,"abstract":"Semantic subtyping is an approach to define subtyping relations for type systems featuring union and intersection type connectives. It has been studied only for strict languages, and it is unsound for non-strict semantics. In this work, we study how to adapt this approach to non-strict languages: in particular, we define a type system using semantic subtyping for a functional language with a call-by-need semantics. We do so by introducing an explicit representation for divergence in the types, so that the type system distinguishes expressions that are results from those which are computations that might diverge.","PeriodicalId":131421,"journal":{"name":"Types for Proofs and Programs","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128671549","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":"Cubical Assemblies, a Univalent and Impredicative Universe and a Failure of Propositional Resizing","authors":"Taichi Uemura","doi":"10.4230/LIPIcs.TYPES.2018.7","DOIUrl":"https://doi.org/10.4230/LIPIcs.TYPES.2018.7","url":null,"abstract":"We construct a model of cubical type theory with a univalent and impredicative universe in a category of cubical assemblies. We show that this impredicative universe in the cubical assembly model does not satisfy a form of propositional resizing.","PeriodicalId":131421,"journal":{"name":"Types for Proofs and Programs","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134560294","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}
Andrej Bauer, Gaëtan Gilbert, Philipp G. Haselwarter, Matija Pretnar, Christopher A. Stone
{"title":"Design and Implementation of the Andromeda Proof Assistant","authors":"Andrej Bauer, Gaëtan Gilbert, Philipp G. Haselwarter, Matija Pretnar, Christopher A. Stone","doi":"10.4230/LIPIcs.TYPES.2016.5","DOIUrl":"https://doi.org/10.4230/LIPIcs.TYPES.2016.5","url":null,"abstract":"Andromeda is an LCF-style proof assistant where the user builds derivable judgments by writing code in a meta-level programming language AML. The only trusted component of Andromeda is a minimalist nucleus (an implementation of the inference rules of an object-level type theory), which controls construction and decomposition of type-theoretic judgments. \u0000Since the nucleus does not perform complex tasks like equality checking beyond syntactic equality, this responsibility is delegated to the user, who implements one or more equality checking procedures in the meta-language. The AML interpreter requests witnesses of equality from user code using the mechanism of algebraic operations and handlers. Dynamic checks in the nucleus guarantee that no invalid object-level derivations can be constructed. %even if the AML code (or interpreter) is untrusted. \u0000To demonstrate the flexibility of this system structure, we implemented a nucleus consisting of dependent type theory with equality reflection. Equality reflection provides a very high level of expressiveness, as it allows the user to add new judgmental equalities, but it also destroys desirable meta-theoretic properties of type theory (such as decidability and strong normalization). \u0000The power of effects and handlers in AML is demonstrated by a standard library that provides default algorithms for equality checking, computation of normal forms, and implicit argument filling. Users can extend these new algorithms by providing local \"hints\" or by completely replacing these algorithms for particular developments. We demonstrate the resulting system by showing how to axiomatize and compute with natural numbers, by axiomatizing the untyped $lambda$-calculus, and by implementing a simple automated system for managing a universe of types.","PeriodicalId":131421,"journal":{"name":"Types for Proofs and Programs","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128187158","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 Equality of Objects in Categories in Constructive Type Theory","authors":"Erik Palmgren","doi":"10.4230/LIPIcs.TYPES.2017.7","DOIUrl":"https://doi.org/10.4230/LIPIcs.TYPES.2017.7","url":null,"abstract":"In this note we remark on the problem of equality of objects in categories formalized in Martin-Lof's constructive type theory. A standard notion of category in this system is E-category, where no ...","PeriodicalId":131421,"journal":{"name":"Types for Proofs and Programs","volume":"1999 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131187219","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":"Efficient Type Checking for Path Polymorphism","authors":"Juan Edi, Andrés Viso, E. Bonelli","doi":"10.4230/LIPIcs.TYPES.2015.6","DOIUrl":"https://doi.org/10.4230/LIPIcs.TYPES.2015.6","url":null,"abstract":"A type system combining type application, constants as types, union types (associative, commutative and idempotent) and recursive types has recently been proposed for statically typing path polymorphism, the ability to define functions that can operate uniformly over recursively specified applicative data structures. A typical pattern such functions resort to is $x,y$ which decomposes a compound, in other words any applicative tree structure, into its parts. We study type-checking for this type system in two stages. First we propose algorithms for checking type equivalence and subtyping based on coinductive characterizations of those relations. We then formulate a syntax-directed presentation and prove its equivalence with the original one. This yields a type-checking algorithm which unfortunately has exponential time complexity in the worst case. A second algorithm is then proposed, based on automata techniques, which yields a polynomial-time type-checking algorithm.","PeriodicalId":131421,"journal":{"name":"Types for Proofs and Programs","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124644599","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 Normalizing Computation Rule for Propositional Extensionality in Higher-Order Minimal Logic","authors":"Robin Adams, M. Bezem, T. Coquand","doi":"10.4230/LIPIcs.TYPES.2016.3","DOIUrl":"https://doi.org/10.4230/LIPIcs.TYPES.2016.3","url":null,"abstract":"The univalence axiom expresses the principle of extensionality for dependent type theory. However, if we simply add the univalence axiom to type theory, then we lose the property of canonicity - that every closed term computes to a canonical form. A computation becomes `stuck' when it reaches the point that it needs to evaluate a proof term that is an application of the univalence axiom. So we wish to find a way to compute with the univalence axiom. While this problem has been solved with the formulation of cubical type theory, where the computations are expressed using a nominal extension of lambda-calculus, it may be interesting to explore alternative solutions, which do not require such an extension. \u0000As a first step, we present here a system of propositional higher-order minimal logic (PHOML). There are three kinds of typing judgement in PHOML. There are terms which inhabit types, which are the simple types over $Omega$. There are proofs which inhabit propositions, which are the terms of type $Omega$. The canonical propositions are those constructed from $bot$ by implication $supset$. Thirdly, there are paths which inhabit equations $M =_A N$, where $M$ and $N$ are terms of type $A$. There are two ways to prove an equality: reflexivity, and propositional extensionality - logically equivalent propositions are equal. This system allows for some definitional equalities that are not present in cubical type theory, namely that transport along the trivial path is identity. \u0000We present a call-by-name reduction relation for this system, and prove that the system satisfies canonicity: every closed typable term head-reduces to a canonical form. This work has been formalised in Agda.","PeriodicalId":131421,"journal":{"name":"Types for Proofs and Programs","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131385768","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":"Heterogeneous substitution systems revisited","authors":"Benedikt Ahrens, Ralph Matthes","doi":"10.4230/LIPIcs.TYPES.2015.2","DOIUrl":"https://doi.org/10.4230/LIPIcs.TYPES.2015.2","url":null,"abstract":"Matthes and Uustalu (TCS 327(1-2):155-174, 2004) presented a categorical description of substitution systems capable of capturing syntax involving binding which is independent of whether the syntax is made up from least or greatest fixed points. We extend this work in two directions: we continue the analysis by creating more categorical structure, in particular by organizing substitution systems into a category and studying its properties, and we develop the proofs of the results of the cited paper and our new ones in UniMath, a recent library of univalent mathematics formalized in the Coq theorem prover.","PeriodicalId":131421,"journal":{"name":"Types for Proofs and Programs","volume":"252 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133821504","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 Type Theory for Probabilistic and Bayesian Reasoning","authors":"Robin Adams, B. Jacobs","doi":"10.4230/LIPIcs.TYPES.2015.1","DOIUrl":"https://doi.org/10.4230/LIPIcs.TYPES.2015.1","url":null,"abstract":"This paper introduces a novel type theory and logic for probabilistic reasoning. Its logic is quantitative, with fuzzy predicates. It includes normalisation and conditioning of states. This conditioning uses a key aspect that distinguishes our probabilistic type theory from quantum type theory, namely the bijective correspondence between predicates and side-effect free actions (called instrument, or assert, maps). The paper shows how suitable computation rules can be derived from this predicate-action correspondence, and uses these rules for calculating conditional probabilities in two well-known examples of Bayesian reasoning in (graphical) models. Our type theory may thus form the basis for a mechanisation of Bayesian inference. 1998 ACM Subject Classification F.4.1 [Mathematical Logic and Formal Languages]: Mathematical Logic — Lambda calculus and related systems; G.3 [Probability and Statistics]: Probabilistic algorithms; F.3.1 [Logics and Meanings of Programs]: Specifying and Verifying and Reasoning about Programs","PeriodicalId":131421,"journal":{"name":"Types for Proofs and Programs","volume":"225 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133390826","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}