Metamath Proof Explorer


Theorem nfalh

Description: Version of nfal with an 'h' hypothesis, avoiding ax-12 . (Contributed by SN, 11-Feb-2026)

Ref Expression
Hypothesis nfalh.1 ⊢ ( 𝜑 → ∀ 𝑥 𝜑 )
Assertion nfalh Ⅎ 𝑥 ∀ 𝑦 𝜑

Proof

Step Hyp Ref Expression
1 nfalh.1 ⊢ ( 𝜑 → ∀ 𝑥 𝜑 )
2 1 hbal ⊢ ( ∀ 𝑦 𝜑 → ∀ 𝑥 ∀ 𝑦 𝜑 )
3 2 nf5i ⊢ Ⅎ 𝑥 ∀ 𝑦 𝜑