Concepts inHigher Dimensional Multigraphs

Multigraph

In mathematics, a multigraph or pseudograph is a graph which is permitted to have multiple edges, (also called "parallel edges"), that is, edges that have the same end nodes. Thus two vertices may be connected by more than one edge. There are two distinct notions of multiple edges. One says that, as in graphs without multiple edges, the identity of an edge is defined by the nodes it connects, but the same edge can occur several times between these nodes.  more from Wikipedia