Metamath Proof Explorer


Theorem reeflogd

Description: Relationship between the natural logarithm function and the exponential function. (Contributed by Mario Carneiro, 29-May-2016)

Ref Expression
Hypothesis relogcld.1
|- ( ph -> A e. RR+ )
Assertion reeflogd
|- ( ph -> ( exp ` ( log ` A ) ) = A )

Proof

Step Hyp Ref Expression
1 relogcld.1
 |-  ( ph -> A e. RR+ )
2 reeflog
 |-  ( A e. RR+ -> ( exp ` ( log ` A ) ) = A )
3 1 2 syl
 |-  ( ph -> ( exp ` ( log ` A ) ) = A )