Bennett negative binomial abs has Sum

import Lean.Elab.Tactic.Omega
import Mathlib.Analysis.Analytic.Binomial
import Mathlib.Analysis.Complex.Basic
import Mathlib.Analysis.Normed.Ring.Basic
import Mathlib.Analysis.SpecificLimits.Normed
import Mathlib.Data.Sym.Basic
import Mathlib.Data.Sym.Card
import Mathlib.RingTheory.MvPolynomial.Symmetric.Defs
import Mathlib.Tactic.Linarith
import Mathlib.Tactic.NormNum
import Mathlib.Tactic.Positivity
import Mathlib.Tactic.Ring

section
/-!
An elementary analytic majorant for the actual binomial/homogeneous tail that
arises in Bennett's simultaneous approximants.  In contrast to a coefficient
envelope interface, every coefficient of the series below is specified.

The algebraic identification of the residue moments with homogeneous
polynomials is a separate theorem.  This file does not assume that an arbitrary
series is a Bennett residual.  Once that identification is available, the
specialization n = 3k, s = k + 1/2 gives exactly the eta exponent in the paper.
-/

namespace D1Bound5








theorem _root_.D1Bound5.bennett_negative_binomial_abs_hasSum (q r : ℝ)
    (hq : 0 < q) (hr0 : 0 ≤ r) (hr1 : r < 1) :
    HasSum (fun t : ℕ => |Ring.choose (-q) t| * r ^ t)
      (1 / (1 - r) ^ q) := by sorry





end D1Bound5
end