1. of sets. The set that results from combining elements common to two sets S and T, say, usually expressed as
∩ is regarded as an operation on sets, the
intersection operation, which is commutative and associative. Symbolically
When two sets
S and
T intersect in the empty set, the sets are disjoint. Since the intersection operation is associative, it can be extended to deal with the intersection of several sets.
2. of two graphs, G1 and G2. The graph that has as vertices those vertices common to G1 and G2 and as edges those edges common to G1 and G2.