Metamath Proof Explorer


Theorem bj-nnfai

Description: Nonfreeness implies the equivalent of ax-5 , inference form. See nf5ri . (Contributed by BJ, 22-Sep-2024)

Ref Expression
Hypothesis bj-nnfai.1 Ⅎ' 𝑥 𝜑
Assertion bj-nnfai ( 𝜑 → ∀ 𝑥 𝜑 )

Proof

Step Hyp Ref Expression
1 bj-nnfai.1 Ⅎ' 𝑥 𝜑
2 bj-nnfa ( Ⅎ' 𝑥 𝜑 → ( 𝜑 → ∀ 𝑥 𝜑 ) )
3 1 2 ax-mp ( 𝜑 → ∀ 𝑥 𝜑 )