Matching Orderable and Separable Hypergraphs

A perfect matching in a hypergraph is a set of edges that partition the set of vertices. We study the complexity of deciding the existence of a perfect matching in orderable and separable hypergraphs. We show that the class of orderable hypergraphs is strictly contained in the class of separable hypergraphs. Accordingly, we show that for each fixed $k$, deciding perfect matching for orderable $k$-hypergraphs is polynomial time doable, but for each fixed $k\geq 3$, it is NP-complete for separable hypergraphs.