Description: e13 without virtual deduction connectives. Special theorem needed for the Virtual Deduction translation tool. (Contributed by Alan Sare, 28-Oct-2011) (Proof modification is discouraged.) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | ee13.1 | |- ( ph -> ps ) | |
| ee13.2 | |- ( ph -> ( ch -> ( th -> ta ) ) ) | ||
| ee13.3 | |- ( ps -> ( ta -> et ) ) | ||
| Assertion | ee13 | |- ( ph -> ( ch -> ( th -> et ) ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | ee13.1 | |- ( ph -> ps ) | |
| 2 | ee13.2 | |- ( ph -> ( ch -> ( th -> ta ) ) ) | |
| 3 | ee13.3 | |- ( ps -> ( ta -> et ) ) | |
| 4 | 1 3 | syl | |- ( ph -> ( ta -> et ) ) | 
| 5 | 2 4 | syl6d | |- ( ph -> ( ch -> ( th -> et ) ) ) |