`BookProof.ChapterFreeFieldBornFiberStabilizer.signStab_card` (x : EuclideanSpace ℝ (Fin n)) : (signStab x).card = 2 ^ (Finset.univ.filter (fun k => x k = 0)).card
ProvedBookProof.ChapterFreeFieldBornFiberStabilizer.signStab_cardtheoremstimepiece
Prove the following Lean 4 theorem from ChapterFreeFieldBornFiberStabilizer.
BookProof.ChapterFreeFieldBornFiberStabilizer.signStab_card (x : EuclideanSpace ℝ (Fin n)) : (signStab x).card = 2 ^ (Finset.univ.filter (fun k => x k = 0)).card
Formalization note: Lean 4 identifier BookProof.ChapterFreeFieldBornFiberStabilizer.signStab_card.
Preamble
-- Generated from ChapterFreeFieldBornFiberStabilizer.lean — theorem BookProof.ChapterFreeFieldBornFiberStabilizer.signStab_card
import Definitions.Def_ChapterFreeFieldBorn
import Definitions.Def_ChapterFreeFieldBornQuotient
import Definitions.Def_ChapterFreeFieldBornSignGauge
import Definitions.Def_ChapterFreeFieldBornFiberCardGeneral
import Definitions.Def_ChapterFreeFieldBornFiberBounds
import Mathlib
import Definitions.Def_ChapterFreeFieldBornFiberStabilizer
open BookProof.ChapterFreeFieldBornFiberStabilizer
open MeasureTheory
open BookProof.ChapterFreeFieldBorn
open BookProof.ChapterFreeFieldBornQuotient
open BookProof.ChapterFreeFieldBornSignGauge
open BookProof.ChapterFreeFieldBornFiberCardGeneral
open BookProof.ChapterFreeFieldBornFiberBounds
variable {n : ℕ}Formal statement
theorem BookProof.ChapterFreeFieldBornFiberStabilizer.signStab_card (x : EuclideanSpace ℝ (Fin n)) :
(signStab x).card = 2 ^ (Finset.univ.filter (fun k => x k = 0)).card := by sorry