Is subcontrarity a symmetrical, asymmetrical or nonsymmetrical property?

hossman ducks as unintelligible to hossman question whooshes by, narrowly avoiding cranial damage and parting hossman’s hair.

Nonsymmetrical. B can be subcontrary to A without A being subcontrary to B.

Then again, I’m not sure what you’re talking about.

If you’re not, you faked it well, bob. Remember, sincerity, once you can fake that, anything is possible.

welcome to logic, folks. it’s as obscure as school can get.

Oh, right, I looked it up: it’s symmetrical.

answers.com says: subcontrary: A proposition related to another in such a way that both may be true, but both cannot be false.

As this link explains, all of the oppositions are symmetrical, with the exception of subalternation (which is nonsymmetrical, as far as I can tell).