pith. machine review for the scientific record. sign in
theorem proved term proof

totient_mul_of_coprime

show as:
view Lean formalization →

No prose has been written for this declaration yet. The Lean source and graph data below render without it.

generate prose now

formal statement (Lean)

 119theorem totient_mul_of_coprime {m n : ℕ} (h : Nat.Coprime m n) :
 120    totient (m * n) = totient m * totient n := by

proof body

Term-mode proof.

 121  simp [totient, Nat.totient_mul h]
 122
 123/-- The sum of φ(d) over divisors of n equals n: ∑_{d|n} φ(d) = n. -/

used by (1)

From the project-wide theorem graph. These declarations reference this one in their body.

depends on (6)

Lean names referenced from this declaration's body.