Semantic Web Technologies

Abstract

LP Syntax II For n-ary predicate symbol p and terms t1, ..., tn, p(t1, ..., tn) is an atom Examples: p(x), p(a), hasName(john, "John"), married-to(john, mary), hasGrandfather(x, father-of(father-of(x))) A ground atom is an atom without variables Literals: A positive literal is an atom: p(x), q(x), ... A negative literal is a negated atom: not p(x), not q(x), ... A ground literals is a literal without variables Rule: The head of the rule consists of one positive literal H The body of the rule consists of a number of literals B1, ...,Bn H :B1,...,Bn B1, ...,Bn are also called subgoals