Theorem 19.35ri

Description: Inference associated with 19.35 . (Contributed by NM, 12-Mar-1993)

	Ref	Expression
Hypothesis	19.35ri.1	⊢ ( ∀ 𝑥 𝜑 → ∃ 𝑥 𝜓 )
Assertion	19.35ri	⊢ ∃ 𝑥 ( 𝜑 → 𝜓 )

Proof

Step	Hyp	Ref	Expression
1		19.35ri.1	⊢ ( ∀ 𝑥 𝜑 → ∃ 𝑥 𝜓 )
2		19.35	⊢ ( ∃ 𝑥 ( 𝜑 → 𝜓 ) ↔ ( ∀ 𝑥 𝜑 → ∃ 𝑥 𝜓 ) )
3	1 2	mpbir	⊢ ∃ 𝑥 ( 𝜑 → 𝜓 )