Third-Order Idealized Algol with Iteration is Decidable
Résumé
The problems of contextual equivalence and approximation are studied for the third-order fragment of Idealized Algol with iteration (IA ∗ 3 ). They are approached via a combination of game semantics and language theory. It is shown that for each IA∗3 -term one can construct a pushdown automaton recognizing a representation of the strategy in- duced by the term. The automata have some additional properties ensur- ing that the associated equivalence and inclusion problems are solvable in Ptime. This gives an Exptime decision procedure for contextual equiv- alence and approximation for β -normal terms. Exptime-hardness is also shown in this case, even in the absence of iteration.
Domaines
Logique en informatique [cs.LO]
Origine : Fichiers produits par l'(les) auteur(s)
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