Metamath Proof Explorer


Theorem bnj1266

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

Ref Expression
Hypothesis bnj1266.1 ⊢ χ → ∃ x φ ∧ ψ
Assertion bnj1266 ⊢ χ → ∃ x ψ

Proof

Step Hyp Ref Expression
1 bnj1266.1 ⊢ χ → ∃ x φ ∧ ψ
2 simpr ⊢ φ ∧ ψ → ψ
3 1 2 bnj593 ⊢ χ → ∃ x ψ