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Metamath Proof Explorer

Theorem mucl

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

		Ref	Expression
	Assertion	mucl	$⊢ A \in ℕ \to μ (A) \in ℤ$

Step	Hyp	Ref	Expression
1		muf	$⊢ μ : ℕ ⟶ ℤ$
2	1	ffvelcdmi	$⊢ A \in ℕ \to μ (A) \in ℤ$