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 ¬ 𝑥 ∈ 𝑦 → ∀ 𝑦 𝑥 ∈ 𝑧 ) → 𝑦 ∈ 𝑥 ) → 𝑥 = 𝑦 )

Proof

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