Commutator for fermion operators?

1. Feb 1, 2014

pellman

If we have two fermion operators with a known anti-commutator AB+BA, what do we do if we find ourselves with AB-BA in an equation? Does this automatically vanish for fermions? if not, is there anything we can say about in general?

2. Feb 1, 2014

strangerep

Not much. If AB+BA=C, then AB-BA=2AB-C.

3. Feb 1, 2014

pellman

silly me. I'll have to post the whole question later instead.