Metamath Proof Explorer


Theorem axc5c4c711toc7

Description: Rederivation of axc7 from axc5c4c711 . Note that neither axc7 nor ax-11 are required for the rederivation. (Contributed by Andrew Salmon, 14-Jul-2011) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Assertion axc5c4c711toc7 ( ¬ ∀ 𝑥 ¬ ∀ 𝑥 𝜑𝜑 )

Proof

Step Hyp Ref Expression
1 ax-1 ( 𝜑 → ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) )
2 1 alimi ( ∀ 𝑥 𝜑 → ∀ 𝑥 ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) )
3 2 axc4i ( ∀ 𝑥 𝜑 → ∀ 𝑥𝑥 ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) )
4 3 con3i ( ¬ ∀ 𝑥𝑥 ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) → ¬ ∀ 𝑥 𝜑 )
5 4 alimi ( ∀ 𝑥 ¬ ∀ 𝑥𝑥 ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) → ∀ 𝑥 ¬ ∀ 𝑥 𝜑 )
6 5 sps ( ∀ 𝑥𝑥 ¬ ∀ 𝑥𝑥 ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) → ∀ 𝑥 ¬ ∀ 𝑥 𝜑 )
7 6 con3i ( ¬ ∀ 𝑥 ¬ ∀ 𝑥 𝜑 → ¬ ∀ 𝑥𝑥 ¬ ∀ 𝑥𝑥 ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) )
8 pm2.21 ( ¬ ∀ 𝑥𝑥 ¬ ∀ 𝑥𝑥 ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) → ( ∀ 𝑥𝑥 ¬ ∀ 𝑥𝑥 ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) → ( ( 𝜑𝜑 ) → ∀ 𝑥 ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) ) ) )
9 axc5c4c711 ( ( ∀ 𝑥𝑥 ¬ ∀ 𝑥𝑥 ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) → ( ( 𝜑𝜑 ) → ∀ 𝑥 ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) ) ) → ( ∀ 𝑥 ( 𝜑𝜑 ) → ∀ 𝑥 𝜑 ) )
10 8 9 syl ( ¬ ∀ 𝑥𝑥 ¬ ∀ 𝑥𝑥 ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) → ( ∀ 𝑥 ( 𝜑𝜑 ) → ∀ 𝑥 𝜑 ) )
11 sp ( ∀ 𝑥 𝜑𝜑 )
12 10 11 syl6 ( ¬ ∀ 𝑥𝑥 ¬ ∀ 𝑥𝑥 ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) → ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) )
13 pm2.27 ( ∀ 𝑥 ( 𝜑𝜑 ) → ( ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) → 𝜑 ) )
14 id ( 𝜑𝜑 )
15 13 14 mpg ( ( ∀ 𝑥 ( 𝜑𝜑 ) → 𝜑 ) → 𝜑 )
16 7 12 15 3syl ( ¬ ∀ 𝑥 ¬ ∀ 𝑥 𝜑𝜑 )