A→B can be transformed into non-A or non-B (including definition): (A→B)∧ Non-B equals (non-A or B) and non-B equals (non-A, non-B) or (b, non-B) B and non-B must be false, and logical false can be ignored in OR operation (absorption law), so the original formula continues to be transformed into non-A, non-B.

Truth table test: When B is true, whether A, (A→B)∧ non-B is false, so (A→B)∧ non-B is not equivalent to non-A, but equivalent to non-A and non-B.

Substituting B= non-B: (A→B)∧ non-B, there are: (A→ non-B)∧ non-(non-B), that is, (A→ non-B)∧B, so the two formulas are equivalent.