Informally, a pseudograph is a graph with multiple edges (or loops) between the same vertices (or the same vertex). Formally: a pseudograph is a set V of vertices along, a set E of edges, and a function from E to {{ u,v}| u,v in V}. (The function shows which vertices are connected by which edge.) An edge is a loop if () = {} for some vertex in V. See also graph and multigraph.

a non-simple undirected graph in which both graph loops and multiple edges are permitted

A graph that contains a vertex connected to itself by an edge, forming a loop.

A false writing; a spurious document; a forgery.