Description: Closed form of ancoms . (Contributed by Alan Sare, 31-Dec-2011)
Ref | Expression | ||
---|---|---|---|
Assertion | ancomst | |- ( ( ( ph /\ ps ) -> ch ) <-> ( ( ps /\ ph ) -> ch ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ancom | |- ( ( ph /\ ps ) <-> ( ps /\ ph ) ) |
|
2 | 1 | imbi1i | |- ( ( ( ph /\ ps ) -> ch ) <-> ( ( ps /\ ph ) -> ch ) ) |