Metamath Proof Explorer


Theorem ralcom13OLD

Description: Obsolete version of ralcom13 as of 2-Jan-2025. (Contributed by AV, 3-Dec-2021) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Assertion ralcom13OLD ( ∀ 𝑥𝐴𝑦𝐵𝑧𝐶 𝜑 ↔ ∀ 𝑧𝐶𝑦𝐵𝑥𝐴 𝜑 )

Proof

Step Hyp Ref Expression
1 ralcom ( ∀ 𝑥𝐴𝑦𝐵𝑧𝐶 𝜑 ↔ ∀ 𝑦𝐵𝑥𝐴𝑧𝐶 𝜑 )
2 ralcom ( ∀ 𝑥𝐴𝑧𝐶 𝜑 ↔ ∀ 𝑧𝐶𝑥𝐴 𝜑 )
3 2 ralbii ( ∀ 𝑦𝐵𝑥𝐴𝑧𝐶 𝜑 ↔ ∀ 𝑦𝐵𝑧𝐶𝑥𝐴 𝜑 )
4 ralcom ( ∀ 𝑦𝐵𝑧𝐶𝑥𝐴 𝜑 ↔ ∀ 𝑧𝐶𝑦𝐵𝑥𝐴 𝜑 )
5 1 3 4 3bitri ( ∀ 𝑥𝐴𝑦𝐵𝑧𝐶 𝜑 ↔ ∀ 𝑧𝐶𝑦𝐵𝑥𝐴 𝜑 )