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

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



open MeasureTheory Filter Complex

theorem BookProof.SchrodingerCutoff.chi_nonneg (x : ℝ) : 0 ≤ chi x := by sorry