Description: The range of the natural logarithm function is a subset of the complex numbers. (Contributed by Mario Carneiro, 13-May-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | logrncn | ⊢ ( 𝐴 ∈ ran log → 𝐴 ∈ ℂ ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ellogrn | ⊢ ( 𝐴 ∈ ran log ↔ ( 𝐴 ∈ ℂ ∧ - π < ( ℑ ‘ 𝐴 ) ∧ ( ℑ ‘ 𝐴 ) ≤ π ) ) | |
2 | 1 | simp1bi | ⊢ ( 𝐴 ∈ ran log → 𝐴 ∈ ℂ ) |