Theorem mucl

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

	Ref	Expression
Assertion	mucl	$$⊢A\in \mathbb{N}\to \mu \left(A\right)\in \mathbb{Z}$$

Proof

Step	Hyp	Ref	Expression
1		muf	$$⊢\mu :\mathbb{N}⟶\mathbb{Z}$$
2	1	ffvelrni	$$⊢A\in \mathbb{N}\to \mu \left(A\right)\in \mathbb{Z}$$