4,262 research outputs found
Analyzing Individual Proofs as the Basis of Interoperability between Proof Systems
We describe the first results of a project of analyzing in which theories
formal proofs can be ex- pressed. We use this analysis as the basis of
interoperability between proof systems.Comment: In Proceedings PxTP 2017, arXiv:1712.0089
Models and termination of proof reduction in the -calculus modulo theory
We define a notion of model for the -calculus modulo theory and
prove a soundness theorem. We then define a notion of super-consistency and
prove that proof reduction terminates in the -calculus modulo any
super-consistent theory. We prove this way the termination of proof reduction
in several theories including Simple type theory and the Calculus of
constructions
Encoding TLA+ set theory into many-sorted first-order logic
We present an encoding of Zermelo-Fraenkel set theory into many-sorted
first-order logic, the input language of state-of-the-art SMT solvers. This
translation is the main component of a back-end prover based on SMT solvers in
the TLA+ Proof System
The language of Stratified Sets is confluent and strongly normalising
We study the properties of the language of Stratified Sets (first-order logic
with and a stratification condition) as used in TST, TZT, and (with
stratifiability instead of stratification) in Quine's NF. We find that the
syntax forms a nominal algebra for substitution and that stratification and
stratifiability imply confluence and strong normalisation under rewrites
corresponding naturally to -conversion.Comment: arXiv admin note: text overlap with arXiv:1406.406
State space c-reductions for concurrent systems in rewriting logic
We present c-reductions, a state space reduction technique.
The rough idea is to exploit some equivalence relation on states (possibly capturing system regularities) that preserves behavioral properties, and explore the induced quotient system. This is done by means of a canonizer
function, which maps each state into a (non necessarily unique) canonical representative of its equivalence class. The approach exploits the expressiveness of rewriting logic and its realization in Maude to enjoy several advantages over similar approaches: exibility and simplicity in
the definition of the reductions (supporting not only traditional symmetry reductions, but also name reuse and name abstraction); reasoning support for checking and proving correctness of the reductions; and automatization
of the reduction infrastructure via Maude's meta-programming
features. The approach has been validated over a set of representative case studies, exhibiting comparable results with respect to other tools
Paracompositionality, MWEs and Argument Substitution
Multi-word expressions, verb-particle constructions, idiomatically combining
phrases, and phrasal idioms have something in common: not all of their elements
contribute to the argument structure of the predicate implicated by the
expression.
Radically lexicalized theories of grammar that avoid string-, term-, logical
form-, and tree-writing, and categorial grammars that avoid wrap operation,
make predictions about the categories involved in verb-particles and phrasal
idioms. They may require singleton types, which can only substitute for one
value, not just for one kind of value. These types are asymmetric: they can be
arguments only. They also narrowly constrain the kind of semantic value that
can correspond to such syntactic categories. Idiomatically combining phrases do
not subcategorize for singleton types, and they exploit another locally
computable and compositional property of a correspondence, that every syntactic
expression can project its head word. Such MWEs can be seen as empirically
realized categorial possibilities, rather than lacuna in a theory of
lexicalizable syntactic categories.Comment: accepted version (pre-final) for 23rd Formal Grammar Conference,
August 2018, Sofi
Inductive-data-type Systems
In a previous work ("Abstract Data Type Systems", TCS 173(2), 1997), the last
two authors presented a combined language made of a (strongly normalizing)
algebraic rewrite system and a typed lambda-calculus enriched by
pattern-matching definitions following a certain format, called the "General
Schema", which generalizes the usual recursor definitions for natural numbers
and similar "basic inductive types". This combined language was shown to be
strongly normalizing. The purpose of this paper is to reformulate and extend
the General Schema in order to make it easily extensible, to capture a more
general class of inductive types, called "strictly positive", and to ease the
strong normalization proof of the resulting system. This result provides a
computation model for the combination of an algebraic specification language
based on abstract data types and of a strongly typed functional language with
strictly positive inductive types.Comment: Theoretical Computer Science (2002
Probabilistic Program Abstractions
Abstraction is a fundamental tool for reasoning about complex systems.
Program abstraction has been utilized to great effect for analyzing
deterministic programs. At the heart of program abstraction is the relationship
between a concrete program, which is difficult to analyze, and an abstract
program, which is more tractable. Program abstractions, however, are typically
not probabilistic. We generalize non-deterministic program abstractions to
probabilistic program abstractions by explicitly quantifying the
non-deterministic choices. Our framework upgrades key definitions and
properties of abstractions to the probabilistic context. We also discuss
preliminary ideas for performing inference on probabilistic abstractions and
general probabilistic programs
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