Metamath Proof Explorer


Theorem exmidne

Description: Excluded middle with equality and inequality. (Contributed by NM, 3-Feb-2012) (Proof shortened by Wolf Lammen, 17-Nov-2019)

Ref Expression
Assertion exmidne A = B A B

Proof

Step Hyp Ref Expression
1 neqne ¬ A = B A B
2 1 orri A = B A B