How to Make a New Logic

Abstract

We discuss about how to make a new logic with considering a slogan: take the inversion of what you know. Suppose that we have a Gentzen-style logical system S. The operation to make a new logic from S is the following: for all the axioms and rules of S, change the direction of all the arrows occurred in the sequents of the axiom or the rule to the opposite side. We call this operation Stahlization. We consider certain logics in this respect.