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isPositivelyOriented -- whether a matroid is positively oriented



This function determines whether a matroid is positively oriented, using a theorem of da Silva (which checks whether any disjoint circuit-cocircuit pair is non-crossing).

i1 : M = matroid({{0,1},{2,3},{4,5}}, EntryMode => "circuits")

o1 = a "matroid" of rank 3 on 6 elements

o1 : Matroid
i2 : isPositivelyOriented M

o2 = false

See also

Ways to use isPositivelyOriented :

For the programmer

The object isPositivelyOriented is a method function.