AUTOMORPHISM-GROUPS OF PICTURES

A picture is a simple graph together with an edge‐coloring, such that each vertex is incident with exactly one edge of each color. An automorphism of a picture is a graph automorphism that preserves the colors of the edges. We show that every group is isomorphic to the full automorphism group of a picture, and prove that a group is isomorphic to a vertex‐transitive subgroup of the automorphism group of a picture if and only if it can be generated by involutions. Copyright © 1990 Wiley Periodicals, Inc., A Wiley Company