Native diagrammatic soundness and completeness proofs for Peirce’s Existential Graphs (Alpha)

Peirce’s diagrammatic system of Existential Graphs ( $$EG_{\alpha })$$ is a logical proof corresponding to the Propositional Calculus (PL). Most known proofs soundness and completeness for }$$ depend upon translation syntax into that suitable Frege-style system. In this paper, drawing standard results but using native notational framework graphs, we present purely syntactic soundness, hence consistency, , along with two separate are constructive in sense provide an algorithm each case construct formal starting from empty Sheet Assertion, given any expression fact tautology according semantics