English
If ha: Tendsto a atTop to 0, and m ≤ n, then mahlerSeries a evaluated at m equals the finite sum ∑_{i=0}^{n} (m choose i) a_i.
Русский
Если ha: a_n → 0 и m ≤ n, то mahlerSeries(a)(m) равен конечной сумме ∑_{i=0}^{n} (m choose i) a_i.
LaTeX
$$$$ mahlerSeries(a)(m) = \\sum_{i=0}^{n} {m \\choose i} a_i \\quad (m \\le n). $$$$
Lean4
/-- Evaluation of a Mahler series is just the pointwise sum. -/
theorem mahlerSeries_apply (ha : Tendsto a atTop (𝓝 0)) (x : ℤ_[p]) : mahlerSeries a x = ∑' n, mahler n x • a n := by
simp only [mahlerSeries, ← ContinuousMap.tsum_apply (hasSum_mahlerSeries ha).summable, mahlerTerm_apply]