Theorem bj-cbvexiw

Description: Change bound variable. This is to cbvexvw what cbvaliw is to cbvalvw . TODO: move after cbvalivw . (Contributed by BJ, 17-Mar-2020)

	Ref	Expression
Hypotheses	bj-cbvexiw.1	|- ( E. x E. y ps -> E. y ps )
	bj-cbvexiw.2	|- ( ph -> A. y ph )
	bj-cbvexiw.3	|- ( y = x -> ( ph -> ps ) )
Assertion	bj-cbvexiw	|- ( E. x ph -> E. y ps )

Proof

Step	Hyp	Ref	Expression
1		bj-cbvexiw.1	|- ( E. x E. y ps -> E. y ps )
2		bj-cbvexiw.2	|- ( ph -> A. y ph )
3		bj-cbvexiw.3	|- ( y = x -> ( ph -> ps ) )
4	2 3	spimew	|- ( ph -> E. y ps )
5	1 4	bj-sylge	|- ( E. x ph -> E. y ps )