Metamath Proof Explorer


Theorem relogefd

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

Ref Expression
Hypothesis relogefd.1 φA
Assertion relogefd φlogeA=A

Proof

Step Hyp Ref Expression
1 relogefd.1 φA
2 relogef AlogeA=A
3 1 2 syl φlogeA=A