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 ) |
| 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 ) |