
Chapter
1
Negation in Logic Programming
John
C.
Shepherdson
Mathematics Department
University of
Bristol,
England
Abstract
A survey of treatments of negation in logic programming. The following
aspects are discussed: elimination of negation by renaming, definite Horn
programs and queries, the relation between the closed world assumption and
the completed data base, and their relation to negation as failure, negation as
failure for definite Horn programs, special classes of program for which nega-
tion as failure coincides with classical negation applied to the completed data
base or closed world assumption, semantics for negation in terms o