Theorem sbcg

Description: Substitution for a variable not occurring in a wff does not affect it. Distinct variable form of sbcgf . (Contributed by Alan Sare, 10-Nov-2012)

	Ref	Expression
Assertion	sbcg	|- ( A e. V -> ( [. A / x ]. ph <-> ph ) )

Proof

Step	Hyp	Ref	Expression
1		nfv	|- F/ x ph
2	1	sbcgf	|- ( A e. V -> ( [. A / x ]. ph <-> ph ) )