Salvador Lucas

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Context-sensitive rewriting is a refined form of rewriting that explores a smaller reduction space by imposing some fixed restrictions on the replacements. Any Term Rewriting System (TRS) can be given a context-sensitive rewrite relation. In this paper, we review the theory of context-sensitive rewriting and formulate conditions to guarantee the confluence(More)
Context-sensitive rewriting is a simple rewriting restriction which is formalized by imposing fixed restrictions on replacements. Such a restriction is given on a purely syntactic basis: it is given on the arguments of symbols of the signature and inductively extended to arbitrary positions of terms built from those symbols. The termination behavior is not(More)
Reasoning about the termination of equational programs in sophisticated equational languages such as ELAN, MAUDE, OBJ, CAFEOBJ, HASKELL, and so on, requires support for advanced features such as evaluation strategies, rewriting modulo, use of extra variables in conditions, partiality, and expressive type systems (possibly including polymorphism and(More)
Context-sensitive dependency pairs (CS-DPs) are currently the most powerful method for automated termination analysis of contextsensitive rewriting. However, compared to DPs for ordinary rewriting, CS-DPs suffer from two main drawbacks: (a) CS-DPs can be collapsing. This complicates the handling of CS-DPs and makes them less powerful in practice. (b) There(More)
Diagnosis of Functional Programs M. Alpuente, M. Comini, S. Escobar, M. Falaschi, and S. Lucas 1 Departamento de Sistemas Informáticos y Computación-DSIC Technical University of Valencia, Camino de Vera s/n, 46022 Valencia, Spain. {alpuente,sescobar,slucas}@dsic.upv.es 2 Dipartimento di Matematica e Informatica University of Udine, Via delle Scienze 206,(More)
Context-sensitive rewriting (CSR) is a restriction of rewriting which forbids reductions on selected arguments of functions. A replacement map discriminates, for each symbol of the signature, the argument positions on which replacements are allowed. If the replacement restrictions are less restrictive than those expressed by the so-called canon-ical(More)
Lazy rewriting (LR) is intended to improve the termination behavior of TRSs. This is attempted by restricting reductions for selected arguments of functions. Similarly, context-sensitive rewriting (CSR) forbids any reduction on those arguments. We show that, under certain conditions, LR and CSR coincide. On the basis of this result, we also describe a(More)