Theorem nfsabg

Description: Bound-variable hypothesis builder for a class abstraction. Usage of this theorem is discouraged because it depends on ax-13 . See nfsab for a version with more disjoint variable conditions, but not requiring ax-13 . (Contributed by Mario Carneiro, 11-Aug-2016) (New usage is discouraged.)

	Ref	Expression
Hypothesis	nfsabg.1	|- F/ x ph
Assertion	nfsabg	|- F/ x z e. { y | ph }

Proof

Step	Hyp	Ref	Expression
1		nfsabg.1	|- F/ x ph
2	1	nf5ri	|- ( ph -> A. x ph )
3	2	hbabg	|- ( z e. { y | ph } -> A. x z e. { y | ph } )
4	3	nf5i	|- F/ x z e. { y | ph }