Theorem eximi

Description: Inference adding existential quantifier to antecedent and consequent. (Contributed by NM, 10-Jan-1993)

	Ref	Expression
Hypothesis	eximi.1	|- ( ph -> ps )
Assertion	eximi	|- ( E. x ph -> E. x ps )

Proof

Step	Hyp	Ref	Expression
1		eximi.1	|- ( ph -> ps )
2		exim	|- ( A. x ( ph -> ps ) -> ( E. x ph -> E. x ps ) )
3	2 1	mpg	|- ( E. x ph -> E. x ps )