Metamath Proof Explorer


Theorem 2ex2rexrot

Description: Rotate two existential quantifiers and two restricted existential quantifiers. (Contributed by AV, 9-Nov-2023)

Ref Expression
Assertion 2ex2rexrot ( ∃ 𝑥𝑦𝑧𝐴𝑤𝐵 𝜑 ↔ ∃ 𝑧𝐴𝑤𝐵𝑥𝑦 𝜑 )

Proof

Step Hyp Ref Expression
1 rexcom4 ( ∃ 𝑤𝐵𝑥𝑦 𝜑 ↔ ∃ 𝑥𝑤𝐵𝑦 𝜑 )
2 1 rexbii ( ∃ 𝑧𝐴𝑤𝐵𝑥𝑦 𝜑 ↔ ∃ 𝑧𝐴𝑥𝑤𝐵𝑦 𝜑 )
3 rexcom4 ( ∃ 𝑧𝐴𝑥𝑤𝐵𝑦 𝜑 ↔ ∃ 𝑥𝑧𝐴𝑤𝐵𝑦 𝜑 )
4 rexcom4 ( ∃ 𝑤𝐵𝑦 𝜑 ↔ ∃ 𝑦𝑤𝐵 𝜑 )
5 4 rexbii ( ∃ 𝑧𝐴𝑤𝐵𝑦 𝜑 ↔ ∃ 𝑧𝐴𝑦𝑤𝐵 𝜑 )
6 rexcom4 ( ∃ 𝑧𝐴𝑦𝑤𝐵 𝜑 ↔ ∃ 𝑦𝑧𝐴𝑤𝐵 𝜑 )
7 5 6 bitri ( ∃ 𝑧𝐴𝑤𝐵𝑦 𝜑 ↔ ∃ 𝑦𝑧𝐴𝑤𝐵 𝜑 )
8 7 exbii ( ∃ 𝑥𝑧𝐴𝑤𝐵𝑦 𝜑 ↔ ∃ 𝑥𝑦𝑧𝐴𝑤𝐵 𝜑 )
9 2 3 8 3bitrri ( ∃ 𝑥𝑦𝑧𝐴𝑤𝐵 𝜑 ↔ ∃ 𝑧𝐴𝑤𝐵𝑥𝑦 𝜑 )