caa a22 4500 467988544 CHVBK 20180323112538.0 cr unu---uuuuu 170328e19900601xx s 000 0 eng 10.1007/BF03037511 doi (NATIONALLICENCE)springer-10.1007/BF03037511 Ling Tok National University of Singapore, Kent Ridge, 0511, Singapore aut The Prolog not-predicate and negation as failure rule [Elektronische Daten] [Tok Ling] Clark's query evaluation procedure for computing negative information in deductive databases using a "negation as failure” inference rule requires a safe computation rule which may only select negative literals if they are ground. This is a very restrictive condition, which weakens the usefulness of negation as failure in a query evaluation procedure. This paper studies the definition and properties of the "not” predicate defined in most Prolog systems which do not enforce the above mentioned condition of a safe computation rule. We show that the negation in clauses and the "not” Predicate of Prolog are not the same. In fact a Prolog program may not be in clause form. An extended query evaluation procedure with an extended safe computation rule is proposed to evaluate queries which involve the "not” predicate. The soundness and completeness of this extended query evaluation procedure with respect to a class of logic programs are proved. The implementation of such an extended query evaluation procedure in a Prolog system can be implemented by a preprocessor for executing range restricted programs and requires no modification to the interpreter/compiler of an existing Prolog system. We compare this proposed extended query evaluation procedure with the extended program proposed by Lloyd and Topor, and the negation constructs in NU-Prolog. The use of the "not” predicate for integrity constraint checking in deductive databases is also presented. Ohmsha, Ltd. and Springer, 1990 Prolog Not-Predicate nationallicence Negation as Failure nationallicence Clark's Query Evaluation Procedure nationallicence Negative Formula nationallicence Extended Query Evaluation Procedure nationallicence New Generation Computing Springer-Verlag 8/1(1990-06-01), 5-31 0288-3635 8:1<5 1990 8 354 https://doi.org/10.1007/BF03037511 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF03037511 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Ling Tok National University of Singapore, Kent Ridge, 0511, Singapore aut NATIONALLICENCE 773 0- New Generation Computing Springer-Verlag 8/1(1990-06-01), 5-31 0288-3635 8:1<5 1990 8 354 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer