Theorem rmoeq1f

Description: Equality theorem for restricted at-most-one quantifier, with bound-variable hypotheses instead of distinct variable restrictions. (Contributed by Alexander van der Vekens, 17-Jun-2017)

	Ref	Expression
Hypotheses	rmoeq1f.1	|- F/_ x A
	rmoeq1f.2	|- F/_ x B
Assertion	rmoeq1f	|- ( A = B -> ( E* x e. A ph <-> E* x e. B ph ) )

Proof

Step	Hyp	Ref	Expression
1		rmoeq1f.1	|- F/_ x A
2		rmoeq1f.2	|- F/_ x B
3	1 2	nfeq	|- F/ x A = B
4		eleq2	|- ( A = B -> ( x e. A <-> x e. B ) )
5	4	anbi1d	|- ( A = B -> ( ( x e. A /\ ph ) <-> ( x e. B /\ ph ) ) )
6	3 5	mobid	|- ( A = B -> ( E* x ( x e. A /\ ph ) <-> E* x ( x e. B /\ ph ) ) )
7		df-rmo	|- ( E* x e. A ph <-> E* x ( x e. A /\ ph ) )
8		df-rmo	|- ( E* x e. B ph <-> E* x ( x e. B /\ ph ) )
9	6 7 8	3bitr4g	|- ( A = B -> ( E* x e. A ph <-> E* x e. B ph ) )