OAI/GroupTheory/PolycyclicRecognition/Analysis/SupportPolytope.lean

GitHub source file

10 declarations, 0 contain sorry, 0 declared as axioms

The finite covector body of the segment support norm

The positive-part formula is the maximum of finitely many actual linear forms, obtained by choosing subsets of the weights in a word basis. This constructs the support body used to define the finite height-label group.

  1. def OAI.PolycyclicRecognition.SupportDatum.supportForm line 28

    Source documentation

    A linear piece in the positive-part expression for segment support.

    def supportForm (b : B) (S : Finset I) : W →L[ℝ] ℝ :=
    …
  2. theorem OAI.PolycyclicRecognition.SupportDatum.supportForm_apply line 32
  3. def OAI.PolycyclicRecognition.SupportDatum.supportForms line 37

    Source documentation

    The explicitly finite set of all linear pieces.

    def supportForms : Finset (W →L[ℝ] ℝ) := by
    …
  4. theorem OAI.PolycyclicRecognition.SupportDatum.mem_supportForms line 42
  5. theorem OAI.PolycyclicRecognition.SupportDatum.supportForm_le line 46
  6. theorem OAI.PolycyclicRecognition.SupportDatum.exists_supportForm_eq line 61

    Source documentation

    Every support value is attained by a member of the finite covector set.

    theorem exists_supportForm_eq (w : W) :
        ∃ φ ∈ D.supportForms, φ w = D.segmentSupport w := by
    …
  7. theorem OAI.PolycyclicRecognition.SupportDatum.supportForms_le line 78
  8. theorem OAI.PolycyclicRecognition.SupportDatum.supportForms_separate line 85

    Source documentation

    The finite pieces still separate the entire height space.

    theorem supportForms_separate (w : W)
        (hw : ∀ φ ∈ D.supportForms, φ w = 0) : w = 0 := by
    …
  9. theorem OAI.PolycyclicRecognition.SupportDatum.supportForms_span line 91

    Source documentation

    The concrete support forms span the continuous dual height space.

    theorem supportForms_span : Submodule.span ℝ (D.supportForms : Set (W →L[ℝ] ℝ)) = ⊤ := by
    …
  10. theorem OAI.PolycyclicRecognition.SupportDatum.mem_supportBody_iff line 113

    Source documentation

    The finite convex body is exactly the set of covectors dominated by the segment support. This is the polarity step used to detect its symmetries.

    theorem mem_supportBody_iff (φ : W →L[ℝ] ℝ) :
        φ ∈ convexHull ℝ (D.supportForms : Set (W →L[ℝ] ℝ)) ↔
          ∀ w, φ w ≤ D.segmentSupport w := by
    …