[A says: “I disapprove of what you say, but I will defend to the death your right to say it”, apocryphal quotation atributed to Voltaire] XNOR [B says: "Where (or of what) one cannot speak, one must pass over in silence" Proposition 7, Tractatus Logico-Philosophicus, Ludwig Wittgenstein]
TsA ≠ TfB, TsB ≠ TfB
TsA ≠ TsB, TfA ≠ TsB
TfA ≠ TsA, TfA ≠ TfB
Thus
A ≠ B
Q.E.D.
