Description: Theorem joining the consequents of two premises. Theorem 8 of Margaris p. 60. (Contributed by NM, 5-Aug-1993) (Proof shortened by Josh Purinton, 29-Dec-2000)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | jcn | |- ( ph -> ( -. ps -> -. ( ph -> ps ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | pm2.27 | |- ( ph -> ( ( ph -> ps ) -> ps ) ) |
|
| 2 | 1 | con3d | |- ( ph -> ( -. ps -> -. ( ph -> ps ) ) ) |