OAI/Analysis/Nonexpansive/TailMaps.lean

GitHub source file

22 declarations, 0 contain sorry, 0 declared as axioms

Resolvent tail families

The outer resolvent in every tail map gives a uniform approximate fixed point bound. Convex hulls are taken in the ambient vector space of maps. Precomposition is linear on that vector space; only this linear operation is distributed over convex combinations.

  1. def OAI.ReflexiveFixedPoints.tailFamily line 28

    Source documentation

    Tail maps retain their actual outer resolvent and generated inner map.

    def tailFamily (m : ℕ) : Set (K → K) :=
    …
  2. theorem OAI.ReflexiveFixedPoints.tailFamily_nonempty line 33
  3. theorem OAI.ReflexiveFixedPoints.tailFamily_generated line 38
  4. theorem OAI.ReflexiveFixedPoints.tailFamily_antitone line 44
  5. theorem OAI.ReflexiveFixedPoints.tailFamily_nonexpansive line 49
  6. theorem OAI.ReflexiveFixedPoints.tailFamily_defect_le line 55
  7. theorem OAI.ReflexiveFixedPoints.tailFamily_precomp line 68

    Source documentation

    Appending any generated map on the input side retains the same tail.

    theorem tailFamily_precomp {m : ℕ} {h g : K → K}
        (hh : h ∈ tailFamily hKclosed hKconvex T hT m)
        (hg : Generated hKclosed hKconvex T hT g) :
        h ∘ g ∈ tailFamily hKclosed hKconvex T hT m := by
    …

    Mentions: OAI.ReflexiveFixedPoints.tailFamily, OAI.ReflexiveFixedPoints.Generated

  8. def OAI.ReflexiveFixedPoints.ambientTailFamily line 76

    Source documentation

    Tail maps represented in the actual vector space of ambient-valued maps.

    def ambientTailFamily (m : ℕ) : Set (K → X) :=
    …
  9. def OAI.ReflexiveFixedPoints.ambientTailConvexHull line 80

    Source documentation

    The algebraic convex hull, before pointwise weak closure is taken.

    def ambientTailConvexHull (m : ℕ) : Set (K → X) :=
    …
  10. theorem OAI.ReflexiveFixedPoints.ambientTailFamily_nonempty line 83
  11. theorem OAI.ReflexiveFixedPoints.ambientTailFamily_antitone line 87
  12. theorem OAI.ReflexiveFixedPoints.ambientTailConvexHull_nonempty line 92
  13. theorem OAI.ReflexiveFixedPoints.ambientTailConvexHull_antitone line 96
  14. theorem OAI.ReflexiveFixedPoints.convex_ambientTailConvexHull line 101
  15. theorem OAI.ReflexiveFixedPoints.ambientTailFamily_subset_generated line 105
  16. theorem OAI.ReflexiveFixedPoints.ambientTailConvexHull_subset_generated line 111
  17. theorem OAI.ReflexiveFixedPoints.ambientTailConvexHull_representative line 118

    Source documentation

    Every element of the ambient convex hull is a genuine generated selfmap.

    theorem ambientTailConvexHull_representative {m : ℕ} {f : K → X}
        (hf : f ∈ ambientTailConvexHull hKclosed hKconvex T hT m) :
        ∃ g : K → K, Generated hKclosed hKconvex T hT g ∧ ambientMap g = f :=
    …

    Mentions: OAI.ReflexiveFixedPoints.ambientTailConvexHull, OAI.ReflexiveFixedPoints.Generated, OAI.ReflexiveFixedPoints.ambientMap

  18. theorem OAI.ReflexiveFixedPoints.ambientTailConvexHull_mapsTo line 123
  19. theorem OAI.ReflexiveFixedPoints.ambientTailConvexHull_nonexpansive line 130
  20. def OAI.ReflexiveFixedPoints.precompLinear line 140

    Source documentation

    Precomposition by a fixed selfmap is a linear map on ambient-valued maps.

    def precompLinear (g : K → K) : (K → X) →ₗ[ℝ] (K → X) where
    …
  21. theorem OAI.ReflexiveFixedPoints.ambientTailConvexHull_precomp line 145
  22. theorem OAI.ReflexiveFixedPoints.ambientTailConvexHull_comp line 160

    Source documentation

    Composition closure follows from linear precomposition, without a continuity or affinity assumption on the nonlinear maps.

    theorem ambientTailConvexHull_comp {m : ℕ} {f g : K → K}
        (hf : ambientMap f ∈ ambientTailConvexHull hKclosed hKconvex T hT m)
        (hg : ambientMap g ∈ ambientTailConvexHull hKclosed hKconvex T hT m) :
        ambientMap (f ∘ g) ∈ ambientTailConvexHull hKclosed hKconvex T hT m := by
    …

    Mentions: OAI.ReflexiveFixedPoints.ambientMap, OAI.ReflexiveFixedPoints.ambientTailConvexHull