Description: Commutation of disjuncts in antecedent. (Contributed by NM, 2-Dec-2012)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | orcoms.1 | |- ( ( ph \/ ps ) -> ch ) |
|
| Assertion | orcoms | |- ( ( ps \/ ph ) -> ch ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | orcoms.1 | |- ( ( ph \/ ps ) -> ch ) |
|
| 2 | pm1.4 | |- ( ( ps \/ ph ) -> ( ph \/ ps ) ) |
|
| 3 | 2 1 | syl | |- ( ( ps \/ ph ) -> ch ) |