Metamath Proof Explorer


Theorem mucl

Description: Closure of the Möbius function. (Contributed by Mario Carneiro, 22-Sep-2014)

Ref Expression
Assertion mucl ⊢ A ∈ ℕ → μ ⁡ A ∈ ℤ

Proof

Step Hyp Ref Expression
1 muf ⊢ μ : ℕ ⟶ ℤ
2 1 ffvelcdmi ⊢ A ∈ ℕ → μ ⁡ A ∈ ℤ