Semantics different to that of imperative languages. Introduction to Predicate Calculus Basis of logic programming is formal logic. Propositions Objects in logic programming propositions are represented by simple terms which are either constants or variables. No intrinsic semantics Propositions can be stated to be facts of queries. All propositions can be restricted to clausal form.
Right side is the antecedent, and left side is the consequent.
These propositions either have a single atomic proposition on the left side or an empty left side. The Origins of Prolog Developped by Alain Colmerauer, Philippe Roussel, and Robert Kowalski. Prolog s syntax is a modified version of predicate calculus. Prolog s inferencing method is a restricted form of resolution. The Basic Elements of Prolog C11.6.1.