English

A multigraph with a loop (blue) and three edges with the same endpoints (all red). Not all authors allow multigraphs to have loops.

Noun

multigraph ‎(plural multigraphs)

1. (mathematics, graph theory) A set V (whose elements are called vertices or nodes), taken together with a multiset E, each of whose elements (called an edge or line) is a cardinality-two multisubset of V.
2. (mathematics, graph theory, less commonly) A set V (as before), taken together with a multiset E, each of whose elements is a cardinality-two subset of V.
3. (historical) A combined rotary typesetting and printing machine for office use. The type is transferred semi-automatically by means of keys from a type-supply drum to a printing drum. The printing may be done by means of an inked ribbon to print "typewritten" letters, or directly from inked type or a stereotype plate, as in a printing press.

Related terms

• multisubgraph
• submultigraph

Synonyms

• pseudograph

Hyponyms

• multidigraph