Topics: Digraph - Graph Theory
(definition)
A symmetric digraph is a digraph where, for every connected pair of vertices , there exists an arc that goes and another one that goes (i.e. a pair of recurring arcs).
Complete vs. Symmetric
A complete digraph is very similar to a symmetric digraph. The difference is that a complete digraph contains a pair of recurring arcs between every pair of vertices, but a symmetric digraph only contains a pair of recurring arcs where a connection already exists.
All complete digraphs are symmetric, but not all symmetric digraphs are complete.