Description: Closure of the divisor function. (Contributed by Mario Carneiro, 22-Sep-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | sgmcl | ⊢ ( ( 𝐴 ∈ ℂ ∧ 𝐵 ∈ ℕ ) → ( 𝐴 σ 𝐵 ) ∈ ℂ ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sgmf | ⊢ σ : ( ℂ × ℕ ) ⟶ ℂ | |
2 | 1 | fovcl | ⊢ ( ( 𝐴 ∈ ℂ ∧ 𝐵 ∈ ℕ ) → ( 𝐴 σ 𝐵 ) ∈ ℂ ) |