Description: Right-to-left inference form of dfvd2 . (Contributed by Alan Sare, 14-Nov-2011) (Proof modification is discouraged.) (New usage is discouraged.)
Ref | Expression | ||
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Hypothesis | dfvd2ir.1 | |- ( ph -> ( ps -> ch ) ) |
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Assertion | dfvd2ir | |- (. ph ,. ps ->. ch ). |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dfvd2ir.1 | |- ( ph -> ( ps -> ch ) ) |
|
2 | dfvd2 | |- ( (. ph ,. ps ->. ch ). <-> ( ph -> ( ps -> ch ) ) ) |
|
3 | 1 2 | mpbir | |- (. ph ,. ps ->. ch ). |