Theorem rabbii

Description: Equivalent wff's correspond to equal restricted class abstractions. Inference form of rabbidv . (Contributed by Peter Mazsa, 1-Nov-2019)

	Ref	Expression
Hypothesis	rabbii.1	|- ( ph <-> ps )
Assertion	rabbii	|- { x e. A | ph } = { x e. A | ps }

Proof

Step	Hyp	Ref	Expression
1		rabbii.1	|- ( ph <-> ps )
2	1	a1i	|- ( x e. A -> ( ph <-> ps ) )
3	2	rabbiia	|- { x e. A | ph } = { x e. A | ps }