An Alternative Proof of Dilworth's Theorem via Local Chain Merges

Abstract

Several elegant proofs of Dilworth's theorem for finite posets already exist in the literature. In this note, we present an alternative inductive proof using a local legal merge lemma on chain ends. By combining this lemma with the bound established by Dilworth's theorem, we observe a direct consequence: every chain decomposition can be transformed into a minimal chain decomposition through a finite sequence of such legal merges

v2: Added acknowledgements v3: Added the structural corollary, refined abstract