Theorem rmobii 2621

Description: Formula-building rule for restricted existential quantifier (inference form). (Contributed by NM, 16-Jun-2017.)

Hypothesis

Ref	Expression
rmobii.1	|- ( ph <-> ps )

Assertion

Ref	Expression
rmobii	|- ( E* x e. A ph <-> E* x e. A ps )

Proof of Theorem rmobii

Step	Hyp	Ref	Expression
1		rmobii.1	. . 3 |- ( ph <-> ps )
2	1	a1i 9	. 2 |- ( x e. A -> ( ph <-> ps ) )
3	2	rmobiia 2620	1 |- ( E* x e. A ph <-> E* x e. A ps )

Syntax hints:   <-> wb 104   e. wcel 1480   E*wrmo 2419

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-5 1423  ax-gen 1425  ax-ie1 1469  ax-ie2 1470  ax-4 1487  ax-17 1506  ax-ial 1514

This theorem depends on definitions:  df-bi 116  df-tru 1334  df-nf 1437  df-eu 2002  df-mo 2003  df-rmo 2424

This theorem is referenced by:  infmoti  6915