In any matroid, all basis elements have the same cardinality r (which is the rank of the matroid). The nonbases of a matroid are the subsets of the ground set of cardinality r that are dependent.
Just as with bases and circuits, nonbases are stored via their indices (rather than the elements of the ground set themselves).
|
|
The object nonbases is a method function.
The source of this document is in /build/reproducible-path/macaulay2-1.25.06+ds/M2/Macaulay2/packages/Matroids/doc-Matroids.m2:737:0.