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 )