Description: Inference rule, a copy of a1d . First recursive proof based on the previous instance. (Contributed by Wolf Lammen, 20-Jun-2020) (New usage is discouraged.) (Proof modification is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | wl-impchain-a1-2.a | |- ( ph -> ps ) |
|
| Assertion | wl-impchain-a1-2 | |- ( ph -> ( ch -> ps ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | wl-impchain-a1-2.a | |- ( ph -> ps ) |
|
| 2 | 1 | wl-impchain-a1-1 | |- ( ch -> ( ph -> ps ) ) |
| 3 | 2 | wl-impchain-com-1.2 | |- ( ph -> ( ch -> ps ) ) |