Metamath Proof Explorer


Theorem rpefcld

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+ )

Proof

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+ )