Equational Uniication, Word Uniication, and 2 Nd -order Equational Uniication
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چکیده
For nite convergent term-rewriting systems it is shown that the equational unii-cation problem is recursively independent of the equational matching problem, the word matching problem, and the 2 nd-order equational matching problem. Apart from the latter these results are derived by considering term-rewriting systems on signatures that contain unary function symbols only (that is, string-rewriting systems). Also for this special case 2 nd-order equational matching is shown to be reducible to 1 st-order equational matching. In addition, we present some new decidability results for simultaneous equational matching and uniication. Finally, we compare the word uniication problem to the 2 nd-order equational uniication problem.
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تاریخ انتشار 1996