Metamath Proof Explorer


Theorem neeq2

Description: Equality theorem for inequality. (Contributed by NM, 19-Nov-1994) (Proof shortened by Wolf Lammen, 18-Nov-2019)

Ref Expression
Assertion neeq2 A = B C A C B

Proof

Step Hyp Ref Expression
1 id A = B A = B
2 1 neeq2d A = B C A C B