Theorem dfvd3ir

Description: Right-to-left inference form of dfvd3 . (Contributed by Alan Sare, 14-Nov-2011) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Hypothesis	dfvd3ir.1	|- ( ph -> ( ps -> ( ch -> th ) ) )
Assertion	dfvd3ir	|- (. ph ,. ps ,. ch ->. th ).

Proof

Step	Hyp	Ref	Expression
1		dfvd3ir.1	|- ( ph -> ( ps -> ( ch -> th ) ) )
2		dfvd3	|- ( (. ph ,. ps ,. ch ->. th ). <-> ( ph -> ( ps -> ( ch -> th ) ) ) )
3	1 2	mpbir	|- (. ph ,. ps ,. ch ->. th ).