Description: The exponential of a real number is a positive real. (Contributed by Mario Carneiro, 29-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | rpefcld.1 | |- ( ph -> A e. RR ) |
|
| Assertion | rpefcld | |- ( ph -> ( exp ` A ) e. RR+ ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | rpefcld.1 | |- ( ph -> A e. RR ) |
|
| 2 | rpefcl | |- ( A e. RR -> ( exp ` A ) e. RR+ ) |
|
| 3 | 1 2 | syl | |- ( ph -> ( exp ` A ) e. RR+ ) |