The Existential Graphs of Charles S. Peirce: An Introduction into the Alpha-system

Abstract

Charles S. Peirce (1839-1914) developed a geometric-topological logic notation, "Existential Graphs", divided into three systems: Alfa, Beta and Gamma. These correspond, respectively, to propositional calculus, first order predicate calculus and a kind of modal logic. The aim of this paper is to present an introduction to the Alfa system and to compare it with the traditional notation.