Metamath Proof Explorer


Theorem rpefcl

Description: The exponential of a real number is a positive real. (Contributed by Mario Carneiro, 10-Nov-2013)

Ref Expression
Assertion rpefcl ( 𝐴 ∈ ℝ → ( exp ‘ 𝐴 ) ∈ ℝ+ )

Proof

Step Hyp Ref Expression
1 reefcl ( 𝐴 ∈ ℝ → ( exp ‘ 𝐴 ) ∈ ℝ )
2 efgt0 ( 𝐴 ∈ ℝ → 0 < ( exp ‘ 𝐴 ) )
3 1 2 elrpd ( 𝐴 ∈ ℝ → ( exp ‘ 𝐴 ) ∈ ℝ+ )