Description: This lemma specializes biimt suitably for the proof of norass . (Contributed by Wolf Lammen, 18-Dec-2023)
Ref | Expression | ||
---|---|---|---|
Assertion | norasslem2 | |- ( ph -> ( ps <-> ( ( ph \/ ch ) -> ps ) ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | orc | |- ( ph -> ( ph \/ ch ) ) |
|
2 | biimt | |- ( ( ph \/ ch ) -> ( ps <-> ( ( ph \/ ch ) -> ps ) ) ) |
|
3 | 1 2 | syl | |- ( ph -> ( ps <-> ( ( ph \/ ch ) -> ps ) ) ) |