Programming Languages: Concepts and Implementation

14.2 Propositional Calculus

A background in symbolic logic is essential to understanding how logic programs are constructed and executed. Symbolic logic is a formal system involving both a syntax by which propositions and relationships between propositions are expressed and formal methods by which new propositions can be deduced from axioms (i.e., propositions asserted to be true). The goal of symbolic logic is to provide a formal apparatus by which the validity of these new propositions can be verified. Multiple systems of symbolic logic exist, which offer varying degrees of expressivity in describing and manipulating propositions. A proposition is a statement that is either true or false (e.g., “Pascal is a philosopher”). Propositional logic ...