Theorem exinst

Description: Existential Instantiation. Virtual deduction form of exlimexi . (Contributed by Alan Sare, 21-Apr-2013) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Hypotheses	exinst.1	|- ( ps -> A. x ps )
	exinst.2	|- (. E. x ph ,. ph ->. ps ).
Assertion	exinst	|- ( E. x ph -> ps )

Proof

Step	Hyp	Ref	Expression
1		exinst.1	|- ( ps -> A. x ps )
2		exinst.2	|- (. E. x ph ,. ph ->. ps ).
3	2	dfvd2i	|- ( E. x ph -> ( ph -> ps ) )
4	1 3	exlimexi	|- ( E. x ph -> ps )