Metamath Proof Explorer


Theorem ac8prim

Description: ac8 expanded into primitives. (Contributed by Eric Schmidt, 19-Oct-2025)

Ref Expression
Assertion ac8prim ( ( ∀ 𝑧 ( 𝑧𝑥 → ∃ 𝑤 𝑤𝑧 ) ∧ ∀ 𝑧𝑤 ( ( 𝑧𝑥𝑤𝑥 ) → ( ¬ 𝑧 = 𝑤 → ∀ 𝑦 ( 𝑦𝑧 → ¬ 𝑦𝑤 ) ) ) ) → ∃ 𝑦𝑧 ( 𝑧𝑥 → ∃ 𝑤𝑣 ( ( 𝑣𝑧𝑣𝑦 ) ↔ 𝑣 = 𝑤 ) ) )

Proof

Step Hyp Ref Expression
1 dfac5prim ( CHOICE ↔ ∀ 𝑥 ( ( ∀ 𝑧 ( 𝑧𝑥 → ∃ 𝑤 𝑤𝑧 ) ∧ ∀ 𝑧𝑤 ( ( 𝑧𝑥𝑤𝑥 ) → ( ¬ 𝑧 = 𝑤 → ∀ 𝑦 ( 𝑦𝑧 → ¬ 𝑦𝑤 ) ) ) ) → ∃ 𝑦𝑧 ( 𝑧𝑥 → ∃ 𝑤𝑣 ( ( 𝑣𝑧𝑣𝑦 ) ↔ 𝑣 = 𝑤 ) ) ) )
2 1 axaci ( ( ∀ 𝑧 ( 𝑧𝑥 → ∃ 𝑤 𝑤𝑧 ) ∧ ∀ 𝑧𝑤 ( ( 𝑧𝑥𝑤𝑥 ) → ( ¬ 𝑧 = 𝑤 → ∀ 𝑦 ( 𝑦𝑧 → ¬ 𝑦𝑤 ) ) ) ) → ∃ 𝑦𝑧 ( 𝑧𝑥 → ∃ 𝑤𝑣 ( ( 𝑣𝑧𝑣𝑦 ) ↔ 𝑣 = 𝑤 ) ) )