Metamath Proof Explorer


Theorem rmoeqd

Description: Equality deduction for restricted at-most-one quantifier. (Contributed by Alexander van der Vekens, 17-Jun-2017)

Ref Expression
Hypothesis raleqd.1
|- ( A = B -> ( ph <-> ps ) )
Assertion rmoeqd
|- ( A = B -> ( E* x e. A ph <-> E* x e. B ps ) )

Proof

Step Hyp Ref Expression
1 raleqd.1
 |-  ( A = B -> ( ph <-> ps ) )
2 rmoeq1
 |-  ( A = B -> ( E* x e. A ph <-> E* x e. B ph ) )
3 1 rmobidv
 |-  ( A = B -> ( E* x e. B ph <-> E* x e. B ps ) )
4 2 3 bitrd
 |-  ( A = B -> ( E* x e. A ph <-> E* x e. B ps ) )