PARTITION MATROID HYPERGRAPHS ARE NICE
MEYSAM ALISHAHI, HOSSEIN HAJIABOLHASSAN, AND FRED´ ERIC´ MEUNIER
1. Introduction For a hypergraph , the Kneser hypergraph KG( ) is a graph with vertex set E( ) and two vertices are adjacentH if corresponding edges areH disjoint. Alternation number of aH hyper- graph is a combinatorial parameters defined by the first and second authors [1]. For each x =(xH,x ,...,x ) +, , 0 n, an alternating subsequence of x is a sequence x ,...,x of 1 2 n 2{ } i1 ik nonzero terms of x (i1 <