OAI/Algebra/Finitistic/Selected/SelectedCountCohomology.lean

GitHub source file

5 declarations, 0 contain sorry, 0 declared as axioms

  1. abbrev OAI.LittleFinitistic.SelectedCountCohomology.count line 14

    Source documentation

    The original summand with exactly r square-zero factors in the actual bar complex.

    abbrev count (Y : FiniteSelectionFamily.S.{0}) (r : ℕ) :=
    …
  2. def OAI.LittleFinitistic.SelectedCountCohomology.comparison line 18

    Source documentation

    Its exact standard integer-shift identification with the genuine derived iterate.

    def comparison (Y : FiniteSelectionFamily.S.{0}) (r : ℕ) :
        (object Y r)⟦(r : ℤ)⟧ ≅ count Y r :=
    …

    Mentions: OAI.LittleFinitistic.SelectedCountCohomology.count

  3. theorem OAI.LittleFinitistic.SelectedCountCohomology.isZero_iff line 22
  4. theorem OAI.LittleFinitistic.SelectedCountCohomology.bounded line 27
  5. theorem OAI.LittleFinitistic.SelectedCountCohomology.nonzero_degree line 45

    Source documentation

    Every surviving iterate contributes a nonzero original count class in a homological degree at least r, with an explicit finite upper bound.

    theorem nonzero_degree (Y : FiniteSelectionFamily.S.{0}) (r : ℕ)
        (h : ¬ IsZero (object Y r)) :
        ∃ n : ℕ, r ≤ n ∧ n ≤ r * (3 * length + 5) ∧
          ¬ IsZero ((DerivedCategory.homologyFunctor (ModuleCat D) (-(n : ℤ))).obj (count Y r)) := by
    …

    Mentions: OAI.LittleFinitistic.SelectedCountCohomology.count