Description: Inference rule, a copy of a1dd . A recursive proof depending on previous instances, and demonstrating the proof pattern. (Contributed by Wolf Lammen, 20-Jun-2020) (New usage is discouraged.) (Proof modification is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | wl-impchain-a1-3.a | |- ( ph -> ( ps -> ch ) ) | |
| Assertion | wl-impchain-a1-3 | |- ( ph -> ( ps -> ( th -> ch ) ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | wl-impchain-a1-3.a | |- ( ph -> ( ps -> ch ) ) | |
| 2 | 1 | wl-impchain-a1-2 | |- ( ph -> ( th -> ( ps -> ch ) ) ) | 
| 3 | 2 | wl-impchain-com-2.3 | |- ( ph -> ( ps -> ( th -> ch ) ) ) |