Metamath Proof Explorer

Theorem exintr

Description: Introduce a conjunct in the scope of an existential quantifier. (Contributed by NM, 11-Aug-1993) (Proof shortened by BJ, 16-Sep-2022)

Ref Expression
Assertion exintr x φ ψ x φ x φ ψ


Step Hyp Ref Expression
1 ancl φ ψ φ φ ψ
2 1 aleximi x φ ψ x φ x φ ψ