Features of propositional logic

Abstract

Logic is an old branch of knowledge; we shall be occupied in this paper with the symbolic logic (or also known as mathematical logic). Propositional logic is a branch of symbolic logic which based on bivalence of classical logic. which it was focused in the beginning on two central problems of logic as formal. Namely, how to decide the given conclusion derived from certainly premises is valid or invalid argument. Recently, it plays role in applications in computer sciences and Engineering. To be able to deciding some known facts about mathematical argument, structure programming. We need logic information's. In This present paper, we highlight features of propositional logic, validity, deduction, consistence, sounds, completing and reducible in propositional logic system (PLS), by strict manner mathematical proofs.