Theorem axc5c711toc7 39735

Description: Rederivation of ax-c7 39700 from axc5c711 39733. Note that ax-c7 39700 and ax-11 2195 are not used by the rederivation. The use of alimi 1844 (which uses ax-c5 39698) is allowed since we have already proved axc5c711toc5 39734. (Contributed by NM, 19-Nov-2006.) (Proof modification is discouraged.) (New usage is discouraged.)

Assertion

Ref	Expression
axc5c711toc7	⊢ (¬ ∀𝑥 ¬ ∀𝑥𝜑 → 𝜑)

Proof of Theorem axc5c711toc7

Step	Hyp	Ref	Expression
1		hba1-o 39712	. . . . . 6 ⊢ (∀𝑥𝜑 → ∀𝑥∀𝑥𝜑)
2	1	con3i 155	. . . . 5 ⊢ (¬ ∀𝑥∀𝑥𝜑 → ¬ ∀𝑥𝜑)
3	2	alimi 1844	. . . 4 ⊢ (∀𝑥 ¬ ∀𝑥∀𝑥𝜑 → ∀𝑥 ¬ ∀𝑥𝜑)
4	3	sps-o 39723	. . 3 ⊢ (∀𝑥∀𝑥 ¬ ∀𝑥∀𝑥𝜑 → ∀𝑥 ¬ ∀𝑥𝜑)
5	4	con3i 155	. 2 ⊢ (¬ ∀𝑥 ¬ ∀𝑥𝜑 → ¬ ∀𝑥∀𝑥 ¬ ∀𝑥∀𝑥𝜑)
6		pm2.21 124	. 2 ⊢ (¬ ∀𝑥∀𝑥 ¬ ∀𝑥∀𝑥𝜑 → (∀𝑥∀𝑥 ¬ ∀𝑥∀𝑥𝜑 → ∀𝑥𝜑))
7		axc5c711 39733	. 2 ⊢ ((∀𝑥∀𝑥 ¬ ∀𝑥∀𝑥𝜑 → ∀𝑥𝜑) → 𝜑)
8	5, 6, 7	3syl 19	1 ⊢ (¬ ∀𝑥 ¬ ∀𝑥𝜑 → 𝜑)

This proof depends on syntax axioms:  ¬ wn 3   → wi 4  ∀wal 1568

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-11 2195  ax-c5 39698  ax-c4 39699  ax-c7 39700

This theorem is used by:  axc5c711to11  39736