A vertex-magic edge labeling of a graph is a bijection
for which the vertex weight
has the same value for every graph vertex . A graph admitting such a labeling is a magic
graph in a common graph-labeling sense.
The word "vertex-magic" refers to the constant vertex weights, while "edge labeling" specifies where the labels are placed. This construction is distinct from an edge-magic total labeling, which labels both graph vertices and graph edges and makes the edge weights constant.