Metamath Proof Explorer


Theorem bj-nnfad

Description: Nonfreeness implies the equivalent of ax-5 , deduction form. See nf5rd . (Contributed by BJ, 2-Dec-2023)

Ref Expression
Hypothesis bj-nnfad.1 ⊢ φ → Ⅎ' x ψ
Assertion bj-nnfad ⊢ φ → ψ → ∀ x ψ

Proof

Step Hyp Ref Expression
1 bj-nnfad.1 ⊢ φ → Ⅎ' x ψ
2 bj-nnfa ⊢ Ⅎ' x ψ → ψ → ∀ x ψ
3 1 2 syl ⊢ φ → ψ → ∀ x ψ