Theorem dfvd2i

Description: Inference form of dfvd2 . (Contributed by Alan Sare, 14-Nov-2011) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Hypothesis	dfvd2i.1	|- (. ph ,. ps ->. ch ).
Assertion	dfvd2i	|- ( ph -> ( ps -> ch ) )

Proof

Step	Hyp	Ref	Expression
1		dfvd2i.1	|- (. ph ,. ps ->. ch ).
2		dfvd2	|- ( (. ph ,. ps ->. ch ). <-> ( ph -> ( ps -> ch ) ) )
3	1 2	mpbi	|- ( ph -> ( ps -> ch ) )