An Introduction to Non Classical Logic

This book grew out of lectures. It is intended as an introduction to classical two-valued predicate logic. The restriction to classical logic is not meant to imply that this logic is intrinsically better than other, non-classical logics; however, classical logic is a good introduction to logic because of its simplicity, and a good basis for applications because it is the foundation of classical mathematics, and thus of the exact sciences which are based on it.

This textbook offers a detailed introduction to the methodology and applications of sequent calculus in propositional logic. Unlike other texts concerned with proof theory, emphasis is placed on illustrating how to use sequent calculus to prove a wide range of metatheoretical results. The presentation is elementary and self-contained, with all technical details both formally stated and also informally explained.