Expressiveness of semipositive logic programs with value invention

Generalized Disjunctive Well-Founded Semantics for Logic Programs

10.21236/ada232064 ◽

1990 ◽

Cited By ~ 19

Author(s):

Chitta Baral ◽

Jorge Lobo ◽

Jack Minker

Keyword(s):

Logic Programs

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Logical Decision Problems and Complexity of Logic Programs

Fundamenta Informaticae ◽

10.3233/fi-1987-10102 ◽

1987 ◽

Vol 10 (1) ◽

pp. 1-33

Author(s):

Egon Börger ◽

Ulrich Löwen

Keyword(s):

Fixed Point ◽

Computational Complexity ◽

Decision Problem ◽

Decision Problems ◽

Complexity Classes ◽

Logic Programs ◽

Finite Structures ◽

Syntactic Restrictions

We survey and give new results on logical characterizations of complexity classes in terms of the computational complexity of decision problems of various classes of logical formulas. There are two main approaches to obtain such results: The first approach yields logical descriptions of complexity classes by semantic restrictions (to e.g. finite structures) together with syntactic enrichment of logic by new expressive means (like e.g. fixed point operators). The second approach characterizes complexity classes by (the decision problem of) classes of formulas determined by purely syntactic restrictions on the formation of formulas.

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Y-Logic: A Framework for Reasoning About Chameleonic Programs with Inconsistent Completions

Fundamenta Informaticae ◽

10.3233/fi-1990-13405 ◽

1990 ◽

Vol 13 (4) ◽

pp. 465-483

Author(s):

V.S. Subrahmanian

Keyword(s):

Classical Logic ◽

Logic Program ◽

Logic Programs ◽

Large Subset ◽

General Logic ◽

Traditional Sense

Large logic programs are normally designed by teams of individuals, each of whom designs a subprogram. While each of these subprograms may have consistent completions, the logic program obtained by taking the union of these subprograms may not. However, the resulting program still serves a useful purpose, for a (possibly) very large subset of it still has a consistent completion. We argue that “small” inconsistencies may cause a logic program to have no models (in the traditional sense), even though it still serves some useful purpose. A semantics is developed in this paper for general logic programs which ascribes a very reasonable meaning to general logic programs irrespective of whether they have consistent (in the classical logic sense) completions.

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