Description: Obsolete version of nsyl2 as of 14-Nov-2023. (Contributed by NM, 26-Jun-1994) (Proof modification is discouraged.) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | nsyl2OLD.1 | |- ( ph -> -. ps ) |
|
| nsyl2OLD.2 | |- ( -. ch -> ps ) |
||
| Assertion | nsyl2OLD | |- ( ph -> ch ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | nsyl2OLD.1 | |- ( ph -> -. ps ) |
|
| 2 | nsyl2OLD.2 | |- ( -. ch -> ps ) |
|
| 3 | 2 | a1i | |- ( ph -> ( -. ch -> ps ) ) |
| 4 | 1 3 | mt3d | |- ( ph -> ch ) |