∀ {p : ℕ} [inst : Fact (Nat.Prime p)] {R : Type u_1} [inst_1 : NormedRing R] [inst_2 : Algebra ℤ_[p] R]
  [inst_3 : IsBoundedSMul ℤ_[p] R] [inst_4 : IsUltrametricDist R] [inst_5 : CompleteSpace R] {r : R}
  (hr : Filter.Tendsto (fun x => r ^ x) Filter.atTop (nhds 0)), (PadicInt.addChar_of_value_at_one r hr) 1 = 1 + r