Metamath Proof Explorer


Theorem bnj1517

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

Ref Expression
Hypothesis bnj1517.1 ⊢ A = x | φ ∧ ψ
Assertion bnj1517 ⊢ x ∈ A → ψ

Proof

Step Hyp Ref Expression
1 bnj1517.1 ⊢ A = x | φ ∧ ψ
2 1 bnj1436 ⊢ x ∈ A → φ ∧ ψ
3 2 simprd ⊢ x ∈ A → ψ