Metamath Proof Explorer


Theorem wl-naevhba1v

Description: An instance of hbn1w applied to equality. (Contributed by Wolf Lammen, 7-Apr-2021)

Ref Expression
Assertion wl-naevhba1v ( ¬ ∀ 𝑥 𝑥 = 𝑦 → ∀ 𝑥 ¬ ∀ 𝑥 𝑥 = 𝑦 )

Proof

Step Hyp Ref Expression
1 equequ1 ( 𝑥 = 𝑧 → ( 𝑥 = 𝑦𝑧 = 𝑦 ) )
2 1 hbn1w ( ¬ ∀ 𝑥 𝑥 = 𝑦 → ∀ 𝑥 ¬ ∀ 𝑥 𝑥 = 𝑦 )