intro l _ hlP
case a
s : Sieve
⊢ ∀ n > 0, (n ∈ fun x => ∃ c, P = x * c) → ∑ x ∈ n.divisorsAntidiagonal, ↑(μ x.1) * (ν x.2)⁻¹ = 1 / g n
case a
s : Sieve
l : ℕ
a✝ : l > 0
hlP : l ∈ fun x => ∃ c, P = x * c
⊢ ∑ x ∈ l.divisorsAntidiagonal, ↑(μ x.1) * (ν x.2)⁻¹ = 1 / g l