Basic graph is a graph for which basis set of matroid is consisting of vertex set . two vertexs are adjoining if and only if there are exactly p ( m ) - l commonality elements in their bases . thus it plays an important role in the further studying 基图是一个以拟阵的基集为顶点集的图,使图中的两个顶点是邻接的当且仅当这两个顶点对应的基恰好有p ( m ) - 1个公共元。