Description: The exponential of a real number is a positive real. (Contributed by Mario Carneiro, 29-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | rpefcld.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℝ ) | |
| Assertion | rpefcld | ⊢ ( 𝜑 → ( exp ‘ 𝐴 ) ∈ ℝ+ ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | rpefcld.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℝ ) | |
| 2 | rpefcl | ⊢ ( 𝐴 ∈ ℝ → ( exp ‘ 𝐴 ) ∈ ℝ+ ) | |
| 3 | 1 2 | syl | ⊢ ( 𝜑 → ( exp ‘ 𝐴 ) ∈ ℝ+ ) |