The Lean 4 theorem `chi_eq_one_of_abs_le_one` in the `ChapterSchrodingerCutoffEsa` chapter of the timepiece formalization

-- Generated from ChapterSchrodingerCutoffEsa.lean — theorem BookProof.SchrodingerCutoff.chi_eq_one_of_abs_le_one
import Mathlib
import Definitions.Def_ChapterSchrodingerCutoffEsa
import Definitions.Def_ChapterParityChirality
open BookProof.ChapterParityChirality
open BookProof.SchrodingerCutoff



open MeasureTheory Filter Complex

theorem BookProof.SchrodingerCutoff.chi_eq_one_of_abs_le_one {x : ℝ} (hx : |x| ≤ 1) : chi x = 1 := by sorry