HORN EXTENDED FEATURE STRUCTURES: FAST UNIFICATION WITH NEGATION AND LIMITED DISJUNCTIONy
نویسنده
چکیده
The notion of a Horn extended feature structure (HoXF) is introduced, which is a feature structure constrained so that its only allowable extensions are those satisfying some set of Horn clauses in feature-term logic. HoXF's greatly generalize ordinary feature structures in admitting explicit representation of negative and implicational constraints. In contradis-tinction to the general case in which arbitrary logical constraints are allowed (for which the best known algorithms are exponential), there is a highly tractable algorithm for the uniication of HoXF's.
منابع مشابه
Horn Extended Feature Structures: Fast Unification With Negation And Limited Disjunction
The notion of a Horn extended feature structure (Hoxf) is introduced, which is a feature structure constrained so that its only allowable extensions are those satisfying some set of Horn clauses in feature-term logic. Hoxf’s greatly generalize ordinary feature structures in admitting explicit representation of negative and implicational constraints. In contradistinction to the general case in w...
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