Decomposition theorem on matchable distributive lattices
arXiv:1008.2818 · doi:10.1016/j.dam.2013.09.008
Abstract
A distributive lattice structure has been established on the set of perfect matchings of a plane bipartite graph . We call a lattice {\em matchable distributive lattice} (simply MDL) if it is isomorphic to such a distributive lattice. It is natural to ask which lattices are MDLs. We show that if a plane bipartite graph is elementary, then is irreducible. Based on this result, a decomposition theorem on MDLs is obtained: a finite distributive lattice is an MDL if and only if each factor in any cartesian product decomposition of is an MDL. Two types of MDLs are presented: and , where denotes the cartesian product between -element chain and -element chain, and is a poset implied by any orientation of a tree.
19 pages, 7 figures