Description: Theorem *5.31 of WhiteheadRussell p. 125. (Contributed by NM, 3-Jan-2005)
Ref | Expression | ||
---|---|---|---|
Assertion | pm5.31 | |- ( ( ch /\ ( ph -> ps ) ) -> ( ph -> ( ps /\ ch ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpr | |- ( ( ch /\ ( ph -> ps ) ) -> ( ph -> ps ) ) |
|
2 | simpl | |- ( ( ch /\ ( ph -> ps ) ) -> ch ) |
|
3 | 1 2 | jctird | |- ( ( ch /\ ( ph -> ps ) ) -> ( ph -> ( ps /\ ch ) ) ) |