Description: Deduction introducing triple disjunction. (Contributed by Scott Fenton, 8-Jun-2011)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | 3mixd.1 | |- ( ph -> ps ) |
|
| Assertion | 3mix1d | |- ( ph -> ( ps \/ ch \/ th ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 3mixd.1 | |- ( ph -> ps ) |
|
| 2 | 3mix1 | |- ( ps -> ( ps \/ ch \/ th ) ) |
|
| 3 | 1 2 | syl | |- ( ph -> ( ps \/ ch \/ th ) ) |