Theorem bj-ceqsalv

Description: Remove from ceqsalv dependency on ax-ext (and on df-cleq , df-v , df-clab , df-sb ). (Contributed by BJ, 12-Oct-2019) (Proof modification is discouraged.)

	Ref	Expression
Hypotheses	bj-ceqsalv.1	|- A e. _V
	bj-ceqsalv.2	|- ( x = A -> ( ph <-> ps ) )
Assertion	bj-ceqsalv	|- ( A. x ( x = A -> ph ) <-> ps )

Proof

Step	Hyp	Ref	Expression
1		bj-ceqsalv.1	|- A e. _V
2		bj-ceqsalv.2	|- ( x = A -> ( ph <-> ps ) )
3		nfv	|- F/ x ps
4	3 1 2	bj-ceqsal	|- ( A. x ( x = A -> ph ) <-> ps )