OAI/Analysis/Nonexpansive/Basic.lean

GitHub source file

17 declarations, 0 contain sorry, 0 declared as axioms

Actual norm and weak carriers for the fixed point argument

The public reflexivity predicate uses the continuous bidual. All maps on convex sets use their norm subtypes. Weak convergence takes place on a separate subtype of WeakSpace, so it cannot alter the given norm. The data structures record conclusions of the reduction from actual fixed-point-free counterexamples.

  1. abbrev OAI.ReflexiveFixedPoints.WeakCarrier line 29

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    The weak carrier is distinct from the norm subtype K.

    abbrev WeakCarrier (K : Set X) :=
    …
  2. def OAI.ReflexiveFixedPoints.normToWeak line 33

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    Change only the carrier; both representatives denote the same point.

    def normToWeak (K : Set X) : K ≃ WeakCarrier K where
    …

    Mentions: OAI.ReflexiveFixedPoints.WeakCarrier

  3. theorem OAI.ReflexiveFixedPoints.normToWeak_val line 39
  4. theorem OAI.ReflexiveFixedPoints.normToWeak_symm_val line 42
  5. def OAI.ReflexiveFixedPoints.WeaklyCompact line 46

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    Actual weak compactness in the ambient weak topology.

    def WeaklyCompact (K : Set X) : Prop :=
    …
  6. def OAI.ReflexiveFixedPoints.WeaklyClosed line 50

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    Actual weak closedness in the ambient weak topology.

    def WeaklyClosed (K : Set X) : Prop :=
    …
  7. def OAI.ReflexiveFixedPoints.differenceSpan line 54

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    The norm-closed linear span of the actual differences.

    def differenceSpan (K : Set X) : Submodule ℝ X :=
    …
  8. def OAI.ReflexiveFixedPoints.differenceBall line 58

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    The entire closed unit ball of the difference span, viewed in X.

    def differenceBall (K : Set X) : Set X :=
    …
  9. def OAI.ReflexiveFixedPoints.InvariantSubset line 62

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    Invariance for an ambient subset under a map of the norm subtype.

    def InvariantSubset (K : Set X) (T : K → K) (s : Set X) : Prop :=
    …
  10. def OAI.ReflexiveFixedPoints.MinimalInvariant line 66

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    Minimality concerns genuine norm-closed convex invariant subsets.

    def MinimalInvariant (K : Set X) (T : K → K) : Prop :=
    …
  11. structure OAI.ReflexiveFixedPoints.MinimalInvariantData line 71

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    Structural conclusions obtained from a genuine fixed-point-free map.

    structure MinimalInvariantData where
    …
  12. structure OAI.ReflexiveFixedPoints.NormalizedMinimalData line 86

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    The normalized reduction data, still in the original ambient norm. The normalization producer uses an actual scalar homothety of the set.

    structure NormalizedMinimalData extends MinimalInvariantData (X := X) where
    …

    Mentions: OAI.ReflexiveFixedPoints.MinimalInvariantData

  13. instance OAI.ReflexiveFixedPoints.MinimalInvariantData.(instance at line 95) line 95
  14. instance OAI.ReflexiveFixedPoints.MinimalInvariantData.(instance at line 97) line 97
  15. instance OAI.ReflexiveFixedPoints.NormalizedMinimalData.(instance at line 104) line 104
  16. instance OAI.ReflexiveFixedPoints.NormalizedMinimalData.(instance at line 106) line 106
  17. theorem OAI.ReflexiveFixedPoints.NormalizedMinimalData.norm_sub_le_one line 110

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    Every pair of points is at distance at most the normalized diameter.

    theorem norm_sub_le_one (D : NormalizedMinimalData (X := X)) (x y : D.K) :
    …

    Mentions: OAI.ReflexiveFixedPoints.NormalizedMinimalData