Principal structure of submodular systems and Hitchcock-type independent flows (Q1906849)

The concept of a matroid has been generalized as a submodular system, that is, a pair of a distributive lattice and a submodular function on it. The paper studies properties of the principal structure of such a submoular system and introduces the concept of Hitchcock-type independent flows. ``Previously known results on the principal structures for bipartite matchings, layered mixed matrices and independent matchings can be understood as applications of the present result''.