Metamath Proof Explorer


Theorem bj-19.41t

Description: Closed form of 19.41 from the same axioms as 19.41v . The same is doable with 19.27 , 19.28 , 19.31 , 19.32 , 19.44 , 19.45 . (Contributed by BJ, 2-Dec-2023)

Ref Expression
Assertion bj-19.41t ( Ⅎ' 𝑥 𝜓 → ( ∃ 𝑥 ( 𝜑𝜓 ) ↔ ( ∃ 𝑥 𝜑𝜓 ) ) )

Proof

Step Hyp Ref Expression
1 exancom ( ∃ 𝑥 ( 𝜑𝜓 ) ↔ ∃ 𝑥 ( 𝜓𝜑 ) )
2 bj-19.42t ( Ⅎ' 𝑥 𝜓 → ( ∃ 𝑥 ( 𝜓𝜑 ) ↔ ( 𝜓 ∧ ∃ 𝑥 𝜑 ) ) )
3 1 2 syl5bb ( Ⅎ' 𝑥 𝜓 → ( ∃ 𝑥 ( 𝜑𝜓 ) ↔ ( 𝜓 ∧ ∃ 𝑥 𝜑 ) ) )
4 3 biancomd ( Ⅎ' 𝑥 𝜓 → ( ∃ 𝑥 ( 𝜑𝜓 ) ↔ ( ∃ 𝑥 𝜑𝜓 ) ) )