A general framework for R-unification problems
E-unification (i.e. solving equations modulo an equational theory E) is an essential technique in automated reasoning, functional logic programming and symbolic constraint solving but, in general E-unification is undecidable. In this paper, we focus on R-unification (i.e. E-unification where theories E are presented by term rewriting systems R). We propose a general method based on tree tuple languages which allows one to decide if two terms are unifiable modulo a term rewriting system R and to represent the set of solutions. As an application, we prove a new decidability result using primal grammars.
keywordsR-unification Rewrite techniques Tree languages
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