isBinary M
Determines if M is a binary matroid, i.e. is representable over the field $F_2$ of 2 elements.
A matroid is representable over F_2 iff it does not have U_{2,4} as a minor. However, this method does not go through hasMinor, for efficiency reasons: rather it checks whether the symmetric difference of any 2 distinct circuits is dependent.
Note: in general, determining representability is a difficult computational problem. For instance, assuming access to an independence oracle, it is known that the problem of determining whether a matroid is binary cannot be solved in polynomial time.




The object isBinary is a method function.