Description: e23an without virtual deductions. (Contributed by Alan Sare, 14-Jul-2011) (Proof modification is discouraged.) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | ee23an.1 | |- ( ph -> ( ps -> ch ) ) | |
| ee23an.2 | |- ( ph -> ( ps -> ( th -> ta ) ) ) | ||
| ee23an.3 | |- ( ( ch /\ ta ) -> et ) | ||
| Assertion | ee23an | |- ( ph -> ( ps -> ( th -> et ) ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | ee23an.1 | |- ( ph -> ( ps -> ch ) ) | |
| 2 | ee23an.2 | |- ( ph -> ( ps -> ( th -> ta ) ) ) | |
| 3 | ee23an.3 | |- ( ( ch /\ ta ) -> et ) | |
| 4 | 1 | a1dd | |- ( ph -> ( ps -> ( th -> ch ) ) ) | 
| 5 | 4 2 3 | ee33an | |- ( ph -> ( ps -> ( th -> et ) ) ) |