Termination of Rule-Based Calculi for Uniform Semi-Unification
نویسندگان
چکیده
Uniform semi-unification is a generalization of unification; its efficient algorithms have been extensively studied in (Kapur et al., 1994) and (Oliart&Snyder, 2004). For (uniform) semi-unification, several variants of rule-based calculi are known. But, some of these calculi in the literature lack the termination property, i.e. not all derivations are terminating. We revisit symbolic semi-unification whose solvability coincides with that of uniform semi-unification. We give an abstract criterion of the strategy on which a general rule-based calculus for symbolic semiunification terminates. Based on this, we give an alternative and robust correctness proof of a rule-based uniform semi-unification algorithm.
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