Description: A positive integer is a complex number. (Contributed by Mario Carneiro, 27-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | nnred.1 | |- ( ph -> A e. NN ) |
|
| Assertion | nncnd | |- ( ph -> A e. CC ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | nnred.1 | |- ( ph -> A e. NN ) |
|
| 2 | nnsscn | |- NN C_ CC |
|
| 3 | 2 1 | sselid | |- ( ph -> A e. CC ) |