Description: Alternate proof of 3jcad . (Contributed by Hongxiu Chen, 29-Jun-2025) (Proof modification is discouraged.) Use 3jcad instead. (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | 3jcadALT.1 | |- ( ph -> ( ps -> ch ) ) |
|
| 3jcadALT.2 | |- ( ph -> ( ps -> th ) ) |
||
| 3jcadALT.3 | |- ( ph -> ( ps -> ta ) ) |
||
| Assertion | 3jcadALT | |- ( ph -> ( ps -> ( ch /\ th /\ ta ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 3jcadALT.1 | |- ( ph -> ( ps -> ch ) ) |
|
| 2 | 3jcadALT.2 | |- ( ph -> ( ps -> th ) ) |
|
| 3 | 3jcadALT.3 | |- ( ph -> ( ps -> ta ) ) |
|
| 4 | 1 2 | jcad | |- ( ph -> ( ps -> ( ch /\ th ) ) ) |
| 5 | 4 3 | jcad | |- ( ph -> ( ps -> ( ( ch /\ th ) /\ ta ) ) ) |
| 6 | df-3an | |- ( ( ch /\ th /\ ta ) <-> ( ( ch /\ th ) /\ ta ) ) |
|
| 7 | 5 6 | imbitrrdi | |- ( ph -> ( ps -> ( ch /\ th /\ ta ) ) ) |