Theorem moimdv

Description: The at-most-one quantifier reverses implication, deduction form. (Contributed by Thierry Arnoux, 25-Feb-2017)

	Ref	Expression
Hypothesis	moimdv.1	|- ( ph -> ( ps -> ch ) )
Assertion	moimdv	|- ( ph -> ( E* x ch -> E* x ps ) )

Proof

Step	Hyp	Ref	Expression
1		moimdv.1	|- ( ph -> ( ps -> ch ) )
2	1	alrimiv	|- ( ph -> A. x ( ps -> ch ) )
3		moim	|- ( A. x ( ps -> ch ) -> ( E* x ch -> E* x ps ) )
4	2 3	syl	|- ( ph -> ( E* x ch -> E* x ps ) )