Metamath Proof Explorer


Definition df-ne

Description: Define inequality. (Contributed by NM, 26-May-1993)

Ref Expression
Assertion df-ne AB¬A=B

Detailed syntax breakdown

Step Hyp Ref Expression
0 cA classA
1 cB classB
2 0 1 wne wffAB
3 0 1 wceq wffA=B
4 3 wn wff¬A=B
5 2 4 wb wffAB¬A=B