139,172 research outputs found
Automated verification of termination certificates
In order to increase user confidence, many automated theorem provers provide
certificates that can be independently verified. In this paper, we report on
our progress in developing a standalone tool for checking the correctness of
certificates for the termination of term rewrite systems, and formally proving
its correctness in the proof assistant Coq. To this end, we use the extraction
mechanism of Coq and the library on rewriting theory and termination called
CoLoR
Towards an implementable dependency grammar
The aim of this paper is to define a dependency grammar framework which is
both linguistically motivated and computationally parsable. See the demo at
http://www.conexor.fi/analysers.html#testingComment: 10 page
Factoring Predicate Argument and Scope Semantics : underspecified Semantics with LTAG
In this paper we propose a compositional semantics for lexicalized tree-adjoining grammar (LTAG). Tree-local multicomponent derivations allow separation of the semantic contribution of a lexical item into one component contributing to the predicate argument structure and a second component contributing to scope semantics. Based on this idea a syntax-semantics interface is presented where the compositional semantics depends only on the derivation structure. It is shown that the derivation structure (and indirectly the locality of derivations) allows an appropriate amount of underspecification. This is illustrated by investigating underspecified representations for quantifier scope ambiguities and related phenomena such as adjunct scope and island constraints
Abstract Program Slicing: an Abstract Interpretation-based approach to Program Slicing
In the present paper we formally define the notion of abstract program
slicing, a general form of program slicing where properties of data are
considered instead of their exact value. This approach is applied to a language
with numeric and reference values, and relies on the notion of abstract
dependencies between program components (statements).
The different forms of (backward) abstract slicing are added to an existing
formal framework where traditional, non-abstract forms of slicing could be
compared. The extended framework allows us to appreciate that abstract slicing
is a generalization of traditional slicing, since traditional slicing (dealing
with syntactic dependencies) is generalized by (semantic) non-abstract forms of
slicing, which are actually equivalent to an abstract form where the identity
abstraction is performed on data.
Sound algorithms for computing abstract dependencies and a systematic
characterization of program slices are provided, which rely on the notion of
agreement between program states
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