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 ∈ ℝ
Assertion relogefd ⊢ φ → log ⁡ e A = A

Proof

Step Hyp Ref Expression
1 relogefd.1 ⊢ φ → A ∈ ℝ
2 relogef ⊢ A ∈ ℝ → log ⁡ e A = A
3 1 2 syl ⊢ φ → log ⁡ e A = A