Decidable Call-by-Need Computations in Term Rewriting
DURAND, Irène
Linguistic signs, grammar and meaning: computational logic for natural language [SIGNES]
Laboratoire Bordelais de Recherche en Informatique [LaBRI]
Linguistic signs, grammar and meaning: computational logic for natural language [SIGNES]
Laboratoire Bordelais de Recherche en Informatique [LaBRI]
DURAND, Irène
Linguistic signs, grammar and meaning: computational logic for natural language [SIGNES]
Laboratoire Bordelais de Recherche en Informatique [LaBRI]
< Réduire
Linguistic signs, grammar and meaning: computational logic for natural language [SIGNES]
Laboratoire Bordelais de Recherche en Informatique [LaBRI]
Langue
en
Article de revue
Ce document a été publié dans
Information and Computation. 2005, vol. 2, n° 196, p. 95-126
Elsevier
Résumé en anglais
The theorem of Huet and Lévy stating that for orthogonal rewrite systems (i) every reducible term contains a needed redex and (ii) repeated contraction of needed redexes results in a normal form if the term under consideration ...Lire la suite >
The theorem of Huet and Lévy stating that for orthogonal rewrite systems (i) every reducible term contains a needed redex and (ii) repeated contraction of needed redexes results in a normal form if the term under consideration has a normal form, forms the basis of all results on optimal normalizing strategies for orthogonal rewrite systems. However, needed redexes are not computable in general. In the paper we show how the use of approximations and elementary tree automata techniques allows one to obtain decidable conditions in a simple and elegant way. Surprisingly, by avoiding complicated concepts like index and sequentiality we are able to cover much larger classes of rewrite systems. We also study modularity aspects of the classes in our hierarchy. It turns out that none of the classes is preserved under signature extension. By imposing various conditions we recover the preservation under signature extension. By imposing some more conditions we are able to strengthen the signature extension results to modularity for disjoint and constructor-sharing combinations.< Réduire
Mots clés en anglais
Term Rewriting
Strategies
Call-by-Need
Tree Automata
Origine
Importé de halUnités de recherche