English
The evaluation of Bernoulli polynomials at 0 recovers the Bernoulli numbers: B_n(0) = B_n.
Русский
Значение Бернулли-полиномов в 0 восстанавливает числа Бернулли: B_n(0) = B_n.
LaTeX
$$$\bigl(Bernoulli(n)\bigr).eval(0) = bernoulli(n)$$$
Lean4
@[simp]
theorem bernoulli_eval_zero (n : ℕ) : (bernoulli n).eval 0 = _root_.bernoulli n :=
by
rw [bernoulli, eval_finset_sum, sum_range_succ]
have : ∑ x ∈ range n, _root_.bernoulli x * n.choose x * 0 ^ (n - x) = 0 :=
by
apply sum_eq_zero fun x hx => _
intro x hx
simp [tsub_eq_zero_iff_le, mem_range.1 hx]
simp [this]