What is a Matroid?

Abstract

Matroids were introduced by Whitney in 1935 to try to capture abstractly the essence of dependence. Whitney's definition embraces a surprising diversity of combinatorial structures. Moreover, matroids arise naturally in combinatorial optimization since they are precisely the structures for which the greedy algorithm works. This survey paper introduces matroid theory, presents some of the main theorems in the subject, and identifies some of the major problems of current research interest.