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A Linear Logical Framework
, 1996
"... We present the linear type theory LLF as the forAppeared in the proceedings of the Eleventh Annual IEEE Symposium on Logic in Computer Science  LICS'96 (E. Clarke editor), pp. 264275, New Brunswick, NJ, July 2730 1996. mal basis for a conservative extension of the LF logical framework. LLF c ..."
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Cited by 217 (44 self)
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We present the linear type theory LLF as the forAppeared in the proceedings of the Eleventh Annual IEEE Symposium on Logic in Computer Science  LICS'96 (E. Clarke editor), pp. 264275, New Brunswick, NJ, July 2730 1996. mal basis for a conservative extension of the LF logical framework. LLF combines the expressive power of dependent types with linear logic to permit the natural and concise representation of a whole new class of deductive systems, namely those dealing with state. As an example we encode a version of MiniML with references including its type system, its operational semantics, and a proof of type preservation. Another example is the encoding of a sequent calculus for classical linear logic and its cut elimination theorem. LLF can also be given an operational interpretation as a logic programming language under which the representations above can be used for type inference, evaluation and cutelimination. 1 Introduction A logical framework is a formal system desig...
Automating the Meta Theory of Deductive Systems
, 2000
"... not be interpreted as representing the o cial policies, either expressed or implied, of NSF or the U.S. Government. This thesis describes the design of a metalogical framework that supports the representation and veri cation of deductive systems, its implementation as an automated theorem prover, a ..."
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Cited by 81 (17 self)
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not be interpreted as representing the o cial policies, either expressed or implied, of NSF or the U.S. Government. This thesis describes the design of a metalogical framework that supports the representation and veri cation of deductive systems, its implementation as an automated theorem prover, and experimental results related to the areas of programming languages, type theory, and logics. Design: The metalogical framework extends the logical framework LF [HHP93] by a metalogic M + 2. This design is novel and unique since it allows higherorder encodings of deductive systems and induction principles to coexist. On the one hand, higherorder representation techniques lead to concise and direct encodings of programming languages and logic calculi. Inductive de nitions on the other hand allow the formalization of properties about deductive systems, such as the proof that an operational semantics preserves types or the proof that a logic is is a proof calculus whose proof terms are recursive functions that may be consistent.M +
Some lambda calculus and type theory formalized
 Journal of Automated Reasoning
, 1999
"... Abstract. We survey a substantial body of knowledge about lambda calculus and Pure Type Systems, formally developed in a constructive type theory using the LEGO proof system. On lambda calculus, we work up to an abstract, simplified, proof of standardization for beta reduction, that does not mention ..."
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Cited by 53 (7 self)
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Abstract. We survey a substantial body of knowledge about lambda calculus and Pure Type Systems, formally developed in a constructive type theory using the LEGO proof system. On lambda calculus, we work up to an abstract, simplified, proof of standardization for beta reduction, that does not mention redex positions or residuals. Then we outline the meta theory of Pure Type Systems, leading to the strengthening lemma. One novelty is our use of named variables for the formalization. Along the way we point out what we feel has been learned about general issues of formalizing mathematics, emphasizing the search for formal definitions that are convenient for formal proof and convincingly represent the intended informal concepts.
Five axioms of alphaconversion
 Ninth international Conference on Theorem Proving in Higher Order Logics TPHOL
, 1996
"... Abstract. We present five axioms of namecarrying lambdaterms identified up to alphaconversion—that is, up to renaming of bound variables. We assume constructors for constants, variables, application and lambdaabstraction. Other constants represent a function Fv that returns the set of free variab ..."
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Cited by 51 (0 self)
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Abstract. We present five axioms of namecarrying lambdaterms identified up to alphaconversion—that is, up to renaming of bound variables. We assume constructors for constants, variables, application and lambdaabstraction. Other constants represent a function Fv that returns the set of free variables in a term and a function that substitutes a term for a variable free in another term. Our axioms are (1) equations relating Fv and each constructor, (2) equations relating substitution and each constructor, (3) alphaconversion itself, (4) unique existence of functions on lambdaterms defined by structural iteration, and (5) construction of lambdaabstractions given certain functions from variables to terms. By building a model from de Bruijn’s nameless lambdaterms, we show that our five axioms are a conservative extension of HOL. Theorems provable from the axioms include distinctness, injectivity and an exhaustion principle for the constructors, principles of structural induction and primitive recursion on lambdaterms, Hindley and Seldin’s substitution lemmas and
A Coverage Checking Algorithm for LF
, 2003
"... Coverage checking is the problem of deciding whether any closed term of a given type is an instance of at least one of a given set of patterns. It can be used to verify if a function defined by pattern matching covers all possible cases. This problem has a straightforward solution for the first ..."
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Cited by 40 (12 self)
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Coverage checking is the problem of deciding whether any closed term of a given type is an instance of at least one of a given set of patterns. It can be used to verify if a function defined by pattern matching covers all possible cases. This problem has a straightforward solution for the firstorder, simplytyped case, but is in general undecidable in the presence of dependent types. In this paper we present a terminating algorithm for verifying coverage of higherorder, dependently typed patterns.
The Occurrence of Continuation Parameters in CPS Terms
, 1995
"... We prove an occurrence property about formal parameters of continuations in ContinuationPassing Style (CPS) terms that have been automatically produced by CPS transformation of pure, callbyvalue terms. Essentially, parameters of continuations obey a stacklike discipline. This property was intro ..."
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Cited by 24 (18 self)
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We prove an occurrence property about formal parameters of continuations in ContinuationPassing Style (CPS) terms that have been automatically produced by CPS transformation of pure, callbyvalue terms. Essentially, parameters of continuations obey a stacklike discipline. This property was introduced, but not formally proven, in an earlier work on the DirectStyle transformation (the inverse of the CPS transformation). The proof has been implemented in Elf, a constraint logic programming language based on the logical framework LF. In fact, it was the implementation that inspired the proof. Thus this note also presents a case study of machineassisted proof discovery. All the programs are available in ( ftp.daimi.aau.dk:pub/danvy/Programs/danvypfenningElf93.tar.gz ftp.cs.cmu.edu:user/fp/papers/cpsocc95.tar.gz Most of the research reported here was carried out while the first author visited Carnegie Mellon University in the Spring of 1993. Current address: Olivier Danvy, Ny Munkeg...
On proving syntactic properties of CPS programs
, 1999
"... Higherorder program transformations raise new challenges for proving properties of their output, since they resist traditional, rstorder proof techniques. In this work, we consider (1) the \onepass" continuationpassing style (CPS) transformation, which is secondorder, and (2) the occurrence ..."
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Cited by 22 (8 self)
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Higherorder program transformations raise new challenges for proving properties of their output, since they resist traditional, rstorder proof techniques. In this work, we consider (1) the \onepass" continuationpassing style (CPS) transformation, which is secondorder, and (2) the occurrences of parameters of continuations in its output. To this end, we specify the onepass CPS transformation relationally and we use the proof technique of logical relations.
Residual theory in λcalculus: A formal development
 Journal of Functional Programming
, 1994
"... Abstract. We present the complete development, in Gallina, of the residual theory of βreduction in pure λcalculus. The main result is the Prism Theorem, and its corollary Lévy’s Cube Lemma, a strong form of the parallelmoves lemma, itself a key step towards the confluence theorem and its usual co ..."
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Cited by 20 (2 self)
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Abstract. We present the complete development, in Gallina, of the residual theory of βreduction in pure λcalculus. The main result is the Prism Theorem, and its corollary Lévy’s Cube Lemma, a strong form of the parallelmoves lemma, itself a key step towards the confluence theorem and its usual corollaries (ChurchRosser, uniqueness of normal forms). Gallina is the specification language of the Coq Proof Assistant[7, 11]. It is a specific concrete syntax for its abstract framework, the Calculus of Inductive Constructions[15]. It may be thought of as a smooth mixture of higherorder predicate calculus with recursive definitions, inductively defined datatypes, and inductive predicate definitions reminiscent of logic programming. The development presented here was fully checked in the current distribution version Coq V5.8. We just state the lemmas in the order in which they are proved, omitting the proof justifications. The full transcript is available as a standard library in the distribution of Coq. 1
Mechanically Verifying the Correctness of an Offline Partial Evaluator
, 1995
"... We show that using deductive systems to specify an offline partial evaluator allows its correctness to be mechanically verified. For a mixstyle partial evaluator, we specify bindingtime constraints using a naturaldeduction logic, and the associated program specializer using natural (aka "deducti ..."
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Cited by 12 (3 self)
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We show that using deductive systems to specify an offline partial evaluator allows its correctness to be mechanically verified. For a mixstyle partial evaluator, we specify bindingtime constraints using a naturaldeduction logic, and the associated program specializer using natural (aka "deductive") semantics. These deductive systems can be directly encoded in the Elf programming language  a logic programming language based on the LF logical framework. The specifications are then executable as logic programs. This provides a prototype implementation of the partial evaluator. Moreover, since deductive system proofs are accessible as objects in Elf, many aspects of the partial evaluation correctness proofs (e.g., the correctness of bindingtime analysis) can be coded in Elf and mechanically verified. This work illustrates the utility of declarative programming and of using deductive systems for defining program specialization systems: by exploiting the logical character of definit...
The ChurchRosser Theorem in Isabelle: A Proof Porting Experiment
, 1995
"... This paper describes a proof of the ChurchRosser theorem for the pure calculus formalised in the Isabelle theorem prover. The initial version of the proof is ported from a similar proof done in the Coq proof assistant by Gérard Huet, but a number of optimisations have been performed. The developme ..."
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Cited by 10 (0 self)
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This paper describes a proof of the ChurchRosser theorem for the pure calculus formalised in the Isabelle theorem prover. The initial version of the proof is ported from a similar proof done in the Coq proof assistant by Gérard Huet, but a number of optimisations have been performed. The development involves the introduction of several inductive and recursive definitions and thus gives a good presentation of the inductive package of Isabelle.