Metamath Proof Explorer


Theorem exrot3

Description: Rotate existential quantifiers. (Contributed by NM, 17-Mar-1995)

Ref Expression
Assertion exrot3 ( ∃ 𝑥𝑦𝑧 𝜑 ↔ ∃ 𝑦𝑧𝑥 𝜑 )

Proof

Step Hyp Ref Expression
1 excom13 ( ∃ 𝑥𝑦𝑧 𝜑 ↔ ∃ 𝑧𝑦𝑥 𝜑 )
2 excom ( ∃ 𝑧𝑦𝑥 𝜑 ↔ ∃ 𝑦𝑧𝑥 𝜑 )
3 1 2 bitri ( ∃ 𝑥𝑦𝑧 𝜑 ↔ ∃ 𝑦𝑧𝑥 𝜑 )