Metamath Proof Explorer


Theorem axpowprim

Description: ax-pow without distinct variable conditions or defined symbols. (Contributed by Scott Fenton, 13-Oct-2010)

Ref Expression
Assertion axpowprim ( ∀ 𝑥 ¬ ∀ 𝑦 ( ∀ 𝑥 ( ¬ ∀ 𝑧 ¬ 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) → 𝑦𝑥 ) → 𝑥 = 𝑦 )

Proof

Step Hyp Ref Expression
1 axpownd ( ¬ 𝑥 = 𝑦 → ∃ 𝑥𝑦 ( ∀ 𝑥 ( ∃ 𝑧 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) → 𝑦𝑥 ) )
2 df-ex ( ∃ 𝑧 𝑥𝑦 ↔ ¬ ∀ 𝑧 ¬ 𝑥𝑦 )
3 2 imbi1i ( ( ∃ 𝑧 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) ↔ ( ¬ ∀ 𝑧 ¬ 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) )
4 3 albii ( ∀ 𝑥 ( ∃ 𝑧 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) ↔ ∀ 𝑥 ( ¬ ∀ 𝑧 ¬ 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) )
5 4 imbi1i ( ( ∀ 𝑥 ( ∃ 𝑧 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) → 𝑦𝑥 ) ↔ ( ∀ 𝑥 ( ¬ ∀ 𝑧 ¬ 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) → 𝑦𝑥 ) )
6 5 albii ( ∀ 𝑦 ( ∀ 𝑥 ( ∃ 𝑧 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) → 𝑦𝑥 ) ↔ ∀ 𝑦 ( ∀ 𝑥 ( ¬ ∀ 𝑧 ¬ 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) → 𝑦𝑥 ) )
7 6 exbii ( ∃ 𝑥𝑦 ( ∀ 𝑥 ( ∃ 𝑧 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) → 𝑦𝑥 ) ↔ ∃ 𝑥𝑦 ( ∀ 𝑥 ( ¬ ∀ 𝑧 ¬ 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) → 𝑦𝑥 ) )
8 df-ex ( ∃ 𝑥𝑦 ( ∀ 𝑥 ( ¬ ∀ 𝑧 ¬ 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) → 𝑦𝑥 ) ↔ ¬ ∀ 𝑥 ¬ ∀ 𝑦 ( ∀ 𝑥 ( ¬ ∀ 𝑧 ¬ 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) → 𝑦𝑥 ) )
9 7 8 bitri ( ∃ 𝑥𝑦 ( ∀ 𝑥 ( ∃ 𝑧 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) → 𝑦𝑥 ) ↔ ¬ ∀ 𝑥 ¬ ∀ 𝑦 ( ∀ 𝑥 ( ¬ ∀ 𝑧 ¬ 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) → 𝑦𝑥 ) )
10 1 9 sylib ( ¬ 𝑥 = 𝑦 → ¬ ∀ 𝑥 ¬ ∀ 𝑦 ( ∀ 𝑥 ( ¬ ∀ 𝑧 ¬ 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) → 𝑦𝑥 ) )
11 10 con4i ( ∀ 𝑥 ¬ ∀ 𝑦 ( ∀ 𝑥 ( ¬ ∀ 𝑧 ¬ 𝑥𝑦 → ∀ 𝑦 𝑥𝑧 ) → 𝑦𝑥 ) → 𝑥 = 𝑦 )