OAI/Analysis/SphereIsometry/KuratowskiBasic.lean

GitHub source file

17 declarations, 0 contain sorry, 0 declared as axioms

The Kuratowski measure from finite diameter covers

The infimum uses positive real radii. The boundedness hypotheses ensure that its defining set is nonempty. No compactness theorem or fixed-point principle is part of this definition.

  1. def OAI.Tingley.FiniteDiameterCover line 20

    Source documentation

    A finite family of sets of pairwise diameter at most the given radius.

    def FiniteDiameterCover (H : Set E) (δ : ℝ) : Prop :=
    …
  2. theorem OAI.Tingley.FiniteDiameterCover.of_fintype line 28
  3. theorem OAI.Tingley.FiniteDiameterCover.of_finite line 38
  4. theorem OAI.Tingley.FiniteDiameterCover.empty line 45
  5. theorem OAI.Tingley.FiniteDiameterCover.mono_set line 50
  6. theorem OAI.Tingley.FiniteDiameterCover.mono_radius line 55
  7. theorem OAI.Tingley.FiniteDiameterCover.closure line 60
  8. def OAI.Tingley.coverRadii line 71

    Source documentation

    Positive radii admitting a finite diameter cover.

    def coverRadii (H : Set E) : Set ℝ :=
    …
  9. def OAI.Tingley.chi line 75

    Source documentation

    The Kuratowski measure of noncompactness, on bounded sets.

    noncomputable def chi (H : Set E) : ℝ := sInf (coverRadii H)

    Mentions: OAI.Tingley.coverRadii

  10. theorem OAI.Tingley.coverRadii_bddBelow line 77
  11. theorem OAI.Tingley.coverRadii_nonempty line 80
  12. theorem OAI.Tingley.chi_nonneg line 91
  13. theorem OAI.Tingley.chi_le_of_cover line 94
  14. theorem OAI.Tingley.chi_empty line 106
  15. theorem OAI.Tingley.chi_mono line 111
  16. theorem OAI.Tingley.exists_cover_of_chi_lt line 117
  17. theorem OAI.Tingley.chi_closure line 124