OAI/GroupTheory/PolycyclicRecognition/Analysis/ProfileRegularity.lean

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4 declarations, 0 contain sorry, 0 declared as axioms

From regularity and finite derivative labels to an affine profile

A continuous derivative taking only finitely many values is constant on a connected domain, and the profile is globally affine.

  1. theorem OAI.PolycyclicRecognition.eq_of_continuous_finite_range line 18

    Source documentation

    A continuous map from a connected space into a finite subset is constant.

    theorem eq_of_continuous_finite_range
        {X Y : Type*} [TopologicalSpace X] [PreconnectedSpace X]
        [TopologicalSpace Y] [T1Space Y]
        (f : X → Y) (hf : Continuous f) (hfinite : Set.Finite (Set.range f)) (x y : X) :
        f x = f y := by
    …
  2. theorem OAI.PolycyclicRecognition.affine_of_continuous_finite_derivative line 28

    Source documentation

    A regular profile whose derivatives lie in a finite set has one global linear label. The offset is its value at the identity of the vector space.

    theorem affine_of_continuous_finite_derivative
        {E F : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E]
        [NormedAddCommGroup F] [NormedSpace ℝ F]
        (f : E → F) (A : E → E →L[ℝ] F)
        (hderiv : ∀ x, HasFDerivAt f (A x) x)
        (hcontinuous : Continuous A) (hfinite : Set.Finite (Set.range A)) :
        ∀ x, f x = f 0 + A 0 x := by
    …
  3. theorem OAI.PolycyclicRecognition.mem_closed_of_continuous_ae line 50

    Source documentation

    For a measure positive on open sets, a continuous map lying in a closed set almost everywhere lies there everywhere.

    theorem mem_closed_of_continuous_ae
        {X Y : Type*} [TopologicalSpace X] [MeasurableSpace X]
        [TopologicalSpace Y] [T2Space Y]
        (μ : MeasureTheory.Measure X) [MeasureTheory.Measure.IsOpenPosMeasure μ]
        (f : X → Y) (hf : Continuous f) (S : Set Y) (hS : IsClosed S)
        (hae : ∀ᵐ x ∂μ, f x ∈ S) : ∀ x, f x ∈ S := by
    …
  4. theorem OAI.PolycyclicRecognition.affine_of_contDiff_ae_finite_derivative line 66

    Source documentation

    The almost-everywhere finite-label condition obtained by profile volume comparison suffices after regularity has supplied a continuous derivative.

    theorem affine_of_contDiff_ae_finite_derivative
        {E F : Type*} [NormedAddCommGroup E] [NormedSpace ℝ E] [MeasurableSpace E]
        [NormedAddCommGroup F] [NormedSpace ℝ F]
        (μ : MeasureTheory.Measure E) [MeasureTheory.Measure.IsOpenPosMeasure μ]
        (f : E → F) (hf : ContDiff ℝ 1 f)
        (S : Set (E →L[ℝ] F)) (hS : S.Finite)
        (hae : ∀ᵐ x ∂μ, fderiv ℝ f x ∈ S) :
        ∀ x, f x = f 0 + fderiv ℝ f 0 x := by
    …