Metamath Proof Explorer


Theorem bnj534

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

Ref Expression
Hypothesis bnj534.1 ⊢ χ → ∃ x φ ∧ ψ
Assertion bnj534 ⊢ χ → ∃ x φ ∧ ψ

Proof

Step Hyp Ref Expression
1 bnj534.1 ⊢ χ → ∃ x φ ∧ ψ
2 19.41v ⊢ ∃ x φ ∧ ψ ↔ ∃ x φ ∧ ψ
3 1 2 sylibr ⊢ χ → ∃ x φ ∧ ψ