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+ ) |