The Lean 4 theorem `approxU_zero_param` in the `ChapterStoneUnitary` chapter of the timepiece formalization

-- Generated from ChapterStoneUnitary.lean — theorem BookProof.ChapterStoneResolvent.UnboundedSelfAdjoint.approxU_zero_param
import Mathlib
import Definitions.Def_ChapterStoneUnitary
import Definitions.Def_ChapterStoneEvolution
import Definitions.Def_ChapterStoneGroup
import Definitions.Def_ChapterStoneResolvent
import Definitions.Def_ChapterSirkTrotterKato
open BookProof.ChapterStoneResolvent
open BookProof.ChapterStoneResolvent.UnboundedSelfAdjoint

variable {H : Type*} [NormedAddCommGroup H] [InnerProductSpace ℂ H] [CompleteSpace H]
variable (T : UnboundedSelfAdjoint H)


open scoped InnerProductSpace
open Filter Topology NormedSpace

theorem BookProof.ChapterStoneResolvent.UnboundedSelfAdjoint.approxU_zero_param (t : ℝ) : T.approxU 0 t = 1 := by sorry