3 ms·The negation of a contradiction is a tautology: ¬(A & ¬A) = ¬A | A = True ¯\_(ツ)_/¯by jjgreen 6y agoThe negation of a contradiction is a tautology: ¬(A & ¬A) = ¬A | A = True ¯\_(ツ)_/¯