Theorem rexlimdva

Description: Inference from Theorem 19.23 of Margaris p. 90 (restricted quantifier version). (Contributed by NM, 20-Jan-2007)

	Ref	Expression
Hypothesis	rexlimdva.1	|- ( ( ph /\ x e. A ) -> ( ps -> ch ) )
Assertion	rexlimdva	|- ( ph -> ( E. x e. A ps -> ch ) )

Proof

Step	Hyp	Ref	Expression
1		rexlimdva.1	|- ( ( ph /\ x e. A ) -> ( ps -> ch ) )
2	1	ex	|- ( ph -> ( x e. A -> ( ps -> ch ) ) )
3	2	rexlimdv	|- ( ph -> ( E. x e. A ps -> ch ) )