OAI/GroupTheory/PolycyclicRecognition/Geometry/CartanRayTrace.lean

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1 declarations, 0 contain sorry, 0 declared as axioms

The actual boundary trace is a positive multiple of its generator ray

  1. theorem OAI.PolycyclicRecognition.CartanWordModel.ray_height_trace_pos_multiple line 22

    Source documentation

    The positive pure-word multiplicities in a ray quotient identify its Haar trace with a strictly positive multiple of the chosen height ray.

    theorem ray_height_trace_pos_multiple
        (j : Fin M.letterCount) (c : Fin M.letterCount → ℕ)
        (hout : ∀ i, (M.weight i : H →ₗ[ℝ] ℝ) ∉ positiveWeightRay
          (M.weight j : H →ₗ[ℝ] ℝ) → c i = 0)
        (hcj : 0 < c j) :
        ∃ r : ℝ, 0 < r ∧
          (∑ i, (c i : ℝ) • cartanHeightWeight T H (M.weight i)).comp eW.symm.toLinearMap =
            r • (cartanHeightWeight T H (M.weight j)).comp eW.symm.toLinearMap := by
    …

    Mentions: OAI.PolycyclicRecognition.positiveWeightRay, OAI.PolycyclicRecognition.cartanHeightWeight