digraphoid
English
[edit]Etymology
[edit]Blend of directed + graphoid, after digraph (“directed graph”). Coined by American mathematician George J. Minty in a 1966 article.
Noun
[edit]digraphoid (plural digraphoids)
- (combinatorics) A dual pair of regular matroids.
- [1966, George J. Minty, “On the Axiomatic Foundations of the Theories of Directed Linear Graphs, Electrical Networks and Network-Programming”, in Journal of Mathematics and Mechanics, volume 15, number 3, →JSTOR, pages 506–507:
- We now wish to consider what part of the theory of directed graphs can be built up in the wider context of graphoids/matroids. To this end, we shall introduce the concepts of digraphoid (short for “directed graphoid”) and orientable graphoid. […] A digraphoid is a structure consisting of: (1º) a graphoid, and (2º) a partitioning of each circuit and cocircuit of the graphoid, each being partitioned into two sets; this partitioning is to satisfy the axiom: […]]