OAI/GroupTheory/PolycyclicRecognition/Algebra/ConeAdaptedMaximalBasis.lean

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2 declarations, 0 contain sorry, 0 declared as axioms

The ideal and ambient boxes have the same maximal width exponent

  1. theorem OAI.PolycyclicRecognition.CartanWordModel.exists_cone_adapted_maximal_basis_data line 20

    Source documentation

    Completing a maximal mixed-word ideal basis by pure quotient words gives a maximal ambient word basis, with exactly the same total width.

    theorem exists_cone_adapted_maximal_basis_data
        (bN : Basis (Fin (finrank ℝ (cartanRootIdeal H))) ℝ (cartanRootIdeal H))
        (bI : Basis (Fin (finrank ℝ (M.coneWordIdeal C))) ℝ (M.coneWordIdeal C))
        (s : Fin M.letterCount → ℝ) (hs : ∀ i, 0 ≤ s i)
        (hzero : ∀ i, (M.weight i : H →ₗ[ℝ] ℝ) ∈ C → s i = 0)
        (β : M.ConeIdealBases C) (hβ : M.IsMaximizingConeIdealBasis C bI s β) :
        ∃ (bQ : Basis (Fin (finrank ℝ (cartanRootIdeal H ⧸ (M.coneWordIdeal C).toSubmodule)))
            ℝ (cartanRootIdeal H ⧸ (M.coneWordIdeal C).toSubmodule))
          (q : Fin (finrank ℝ (cartanRootIdeal H ⧸ (M.coneWordIdeal C).toSubmodule)) →
            FreeMagma (Fin M.letterCount)),
          (∀ j, ¬IsMixedWord (fun i => (M.weight i : H →ₗ[ℝ] ℝ) ∉ C) (q j)) ∧
          ∃ hq : ∀ j, (M.coneWordIdeal C).toSubmodule.mkQ (evalBracketWord M.letter (q j)) = bQ j,
    …

    Mentions: OAI.PolycyclicRecognition.cartanRootIdeal, OAI.PolycyclicRecognition.IsMixedWord, OAI.PolycyclicRecognition.evalBracketWord

  2. theorem OAI.PolycyclicRecognition.CartanWordModel.exists_cone_adapted_maximal_basis line 136

    Source documentation

    The adapted ambient basis has exactly the maximal ideal width sum.

    theorem exists_cone_adapted_maximal_basis
        (bN : Basis (Fin (finrank ℝ (cartanRootIdeal H))) ℝ (cartanRootIdeal H))
        (bI : Basis (Fin (finrank ℝ (M.coneWordIdeal C))) ℝ (M.coneWordIdeal C))
        (s : Fin M.letterCount → ℝ) (hs : ∀ i, 0 ≤ s i)
        (hzero : ∀ i, (M.weight i : H →ₗ[ℝ] ℝ) ∈ C → s i = 0)
        (β : M.ConeIdealBases C) (hβ : M.IsMaximizingConeIdealBasis C bI s β) :
        ∃ γ : M.Bases,
          IsMaximizingColumnBasis (wordListCoordinates M.letter M.wordList bN)
            (fun w => bracketWordExponent s w) γ.val ∧
          columnBasisWeight (fun w : M.wordList => bracketWordExponent s w) γ.val =
            columnBasisWeight (fun w : M.coneIdealWordList C => M.coneIdealWordCost C s w) β.val := by
    …

    Mentions: OAI.PolycyclicRecognition.cartanRootIdeal, OAI.PolycyclicRecognition.IsMaximizingColumnBasis, OAI.PolycyclicRecognition.wordListCoordinates, OAI.PolycyclicRecognition.bracketWordExponent, OAI.PolycyclicRecognition.columnBasisWeight