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