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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 ∈ ℕ → ( μ ‘ 𝐴 ) ∈ ℤ )

Proof

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