Theorem bnj1196

Description: First-order logic and set theory. (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)

	Ref	Expression
Hypothesis	bnj1196.1	⊢ ( 𝜑 → ∃ 𝑥 ∈ 𝐴 𝜓 )
Assertion	bnj1196	⊢ ( 𝜑 → ∃ 𝑥 ( 𝑥 ∈ 𝐴 ∧ 𝜓 ) )

Proof

Step	Hyp	Ref	Expression
1		bnj1196.1	⊢ ( 𝜑 → ∃ 𝑥 ∈ 𝐴 𝜓 )
2		df-rex	⊢ ( ∃ 𝑥 ∈ 𝐴 𝜓 ↔ ∃ 𝑥 ( 𝑥 ∈ 𝐴 ∧ 𝜓 ) )
3	1 2	sylib	⊢ ( 𝜑 → ∃ 𝑥 ( 𝑥 ∈ 𝐴 ∧ 𝜓 ) )