The Lean 4 theorem `ext_symmetricOn` in the `ChapterQgOuterFockCoreFL` chapter of the timepiece formalization

-- Generated from ChapterQgOuterFockCoreFL.lean — theorem BookProof.QgOuterFockCoreFL.CoreData.ext_symmetricOn
import Definitions.Def_ChapterFarisLavine
import Definitions.Def_ChapterDirectSumEsa
import Definitions.Def_ChapterQgOuterFockEsa
import Definitions.Def_ChapterQgOuterFockFarisLavine
import Definitions.Def_ChapterYangMillsFriedrichs
import Definitions.Def_ChapterEsaClosureCore
import Definitions.Def_ChapterQgHermiteOscillatorEsa
import Definitions.Def_ChapterHermiteProductCore
import Mathlib
import Definitions.Def_ChapterQgOuterFockCoreFL
import Definitions.Def_ChapterFarisLavineCore
open BookProof.QgOuterFockCoreFL
open BookProof.QgOuterFockCoreFL

variable {F : Type*} [NormedAddCommGroup F] [InnerProductSpace ℂ F] [CompleteSpace F]
variable (d : CoreData F)



open BookProof.FarisLavine
open BookProof.DirectSumEsa
open BookProof.QgOuterFock
open BookProof.QgOuterFockFL
open BookProof.YangMillsFriedrichs
open BookProof.EsaClosure
open BookProof.QgHermiteOscillator
open BookProof.HermiteProductCore
open Filter Topology

noncomputable section

theorem BookProof.QgOuterFockCoreFL.CoreData.ext_symmetricOn (hsym : SymmetricOn d.C₀ d.H₀) : SymmetricOn d.C.dom d.ext := by sorry