This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Description: Alternate proof of axc16nf , shorter but requiring ax-11 and ax-13 . (Contributed by Mario Carneiro, 7-Oct-2016) (Proof modification is discouraged.) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | axc16nfALT | ⊢ ( ∀ 𝑥 𝑥 = 𝑦 → Ⅎ 𝑧 𝜑 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | nfae | ⊢ Ⅎ 𝑧 ∀ 𝑥 𝑥 = 𝑦 | |
| 2 | axc16g | ⊢ ( ∀ 𝑥 𝑥 = 𝑦 → ( 𝜑 → ∀ 𝑧 𝜑 ) ) | |
| 3 | 1 2 | nf5d | ⊢ ( ∀ 𝑥 𝑥 = 𝑦 → Ⅎ 𝑧 𝜑 ) |