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Metamath Proof Explorer

Theorem bj-19.23bit

Description: Closed form of 19.23bi . (Contributed by BJ, 20-Oct-2019)

Ref Expression
Assertion bj-19.23bit ( ( ∃ 𝑥 𝜑 → 𝜓 ) → ( 𝜑 → 𝜓 ) )

Proof

Step Hyp Ref Expression
1 19.8a ⊢ ( 𝜑 → ∃ 𝑥 𝜑 )
2 1 imim1i ⊢ ( ( ∃ 𝑥 𝜑 → 𝜓 ) → ( 𝜑 → 𝜓 ) )