منابع مشابه
Semi-Unification
Kapur, D., D. Musser, P. Narendran and J. Stillman, Semi-unification, Theoretical Computer Science 81 (1991) 169-187. Semi-unification is a generalization of both matching and ordinary unification: for a given pair of terms s and r, two substitutions p and a are sought such that p(a(s)) = a(t). Semi-unifiability can be used as a check for non-termination of a rewrite rule, but constructing a co...
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Semi-unification is a generalization of both unification and matching with applications in proof theory, term rewriting systems, polymorphic type inference, and natural language processing. It is the problem of solving a set of term inequalities M1 ≤ N1, . . . ,Mk ≤ Nk, where ≤ is interpreted as the subsumption preordering on (first-order) terms. Whereas the general problem has recently been sh...
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A recursion scheme is an orthogonal rewriting system with rules of the form f(x1, . . . , xn) → s. We consider terms to be equivalent if they rewrite to the same redex-free possibly infinite term after infinitary rewriting. For the restriction to the nonnested case, where nested redexes are forbidden, we prove the existence of principal unifiers modulo scheme equivalence. We give an algorithm c...
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Uniform semi-unification is a simple combination of matching and unification defined as follows: given two terms s and t , do there exist substitutions σ and ρ such that sσρ = tσ ? We present two algorithms for this problem based on Huet’s unification closure method, one producing (possibly) non-principal solutions, and one producing principal solutions. For both we provide a precise analysis o...
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Program schemas are known to be useful in diierent applications such as program synthesis, transformation, analysis, debugging, teaching : : : This paper tackles two complementary aspects of program schemas. We rst propose a language for the description of program schemas. It is based on a subset of second-order logic, enhanced with constraints and speciic features of program schemas. One of th...
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ژورنال
عنوان ژورنال: Theoretical Computer Science
سال: 1991
ISSN: 0304-3975
DOI: 10.1016/0304-3975(91)90189-9