55theorem mobius_apply_of_squarefree {n : ℕ} (hn : Squarefree n) : 56 mobius n = (-1) ^ ArithmeticFunction.cardFactors n := by
proof body
Term-mode proof.
57 simpa [mobius] using (ArithmeticFunction.moebius_apply_of_squarefree (n := n) hn) 58 59/-- A useful bridge: for `n ≠ 0`, `μ n ≠ 0` iff all prime exponents are ≤ 1. -/
used by (2)
From the project-wide theorem graph. These declarations reference this one in their body.