norm_num
case succ
n : ℕ
h : 2 ≤ n → ∏ x ∈ Ico 1 n.succ, (↑x + 1) / ↑x = ↑n + 1
hn : 2 ≤ n + 1
⊢ (∏ k ∈ Ico 1 (n + 1), (↑k + 1) / ↑k) * ((↑(n + 1) + 1) / ↑(n + 1)) = ↑(n + 1) + 1
case succ
n : ℕ
h : 2 ≤ n → ∏ x ∈ Ico 1 n.succ, (↑x + 1) / ↑x = ↑n + 1
hn : 2 ≤ n + 1
⊢ ((∏ x ∈ Ico 1 (n + 1), (↑x + 1)) / ∏ x ∈ Ico 1 (n + 1), ↑x) * ((↑n + 1 + 1) / (↑n + 1)) = ↑n + 1 + 1