FYI: NOT(A AND B) = NOT(A) OR NOT(B)

However, if you have a patch that implements it in a good way and make it optional then I'll apply it. I think it's possible to do in backwards compatible way and quite natural.

Note that the module supports &, | and other symbols as boolean operators and the same should be applied to NOT operator, so it can be 'NOT', '!' or '-'...