The set of edges of a loopless graph , being a set of unordered pairs of elements of , constitutes an adjacency relation on . Formally, an adjacency relation is any relation which is irreflexive and symmetric.

# Adjacency Relation

## See also

Irreflexive, Relation, Symmetric## Explore with Wolfram|Alpha

## Cite this as:

Weisstein, Eric W. "Adjacency Relation."
From *MathWorld*--A Wolfram Web Resource. https://mathworld.wolfram.com/AdjacencyRelation.html