Theorem rmoimi

Description: Restricted "at most one" is preserved through implication (note wff reversal). (Contributed by Alexander van der Vekens, 17-Jun-2017)

	Ref	Expression
Hypothesis	rmoimi.1	|- ( ph -> ps )
Assertion	rmoimi	|- ( E* x e. A ps -> E* x e. A ph )

Proof

Step	Hyp	Ref	Expression
1		rmoimi.1	|- ( ph -> ps )
2	1	a1i	|- ( x e. A -> ( ph -> ps ) )
3	2	rmoimia	|- ( E* x e. A ps -> E* x e. A ph )