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 φ A
Assertion relogefd φ log e A = A


Step Hyp Ref Expression
1 relogefd.1 φ A
2 relogef A log e A = A
3 1 2 syl φ log e A = A