OAI/Algebra/Finitistic/Bar/Weight.lean

GitHub source file

9 declarations, 0 contain sorry, 0 declared as axioms

  1. inductive OAI.DerivedBar.SquareZero.Word line 18

    Source documentation

    (TrivSqZeroExt D X) pure bar word with precisely r factors in the square-zero ideal.

    inductive Word : (n r : ℕ) → term k (TrivSqZeroExt D X) N n → Prop
      | nil (v : N) : Word 0 0 v
      | base {n r : ℕ} {v : term k (TrivSqZeroExt D X) N n} (d : D) (h : Word n r v) :
          Word (n+1) r ((inl d : (TrivSqZeroExt D X)) ⊗ₜ[k] v)
      | ideal {n r : ℕ} {v : term k (TrivSqZeroExt D X) N n} (x : X) (h : Word n r v) :
          Word (n+1) (r+1) ((inr x : (TrivSqZeroExt D X)) ⊗ₜ[k] v)
    
    /-- The homogeneous subspace, defined by actual tensors rather than formal signs. -/

    Mentions: OAI.DerivedBar.term

  2. def OAI.DerivedBar.SquareZero.weight line 26

    Source documentation

    The homogeneous subspace, defined by actual tensors rather than formal signs.

    def weight (n r : ℕ) : Submodule k (term k (TrivSqZeroExt D X) N n) :=
    …

    Mentions: OAI.DerivedBar.term

  3. theorem OAI.DerivedBar.SquareZero.map_span_mem line 29
  4. theorem OAI.DerivedBar.SquareZero.base_tmul_mem line 37
  5. theorem OAI.DerivedBar.SquareZero.ideal_tmul_mem line 43
  6. theorem OAI.DerivedBar.SquareZero.base_smul_mem line 52

    Source documentation

    Degree-zero multiplication preserves the number of ideal factors.

    theorem base_smul_mem {n r : ℕ} (d : D) {v : term k (TrivSqZeroExt D X) N n}
        (hv : v ∈ weight k D X N n r) :
        (inl d : (TrivSqZeroExt D X)) • v ∈ weight k D X N n r := by
    …

    Mentions: OAI.DerivedBar.term, OAI.DerivedBar.SquareZero.weight

  7. theorem OAI.DerivedBar.SquareZero.ideal_smul_mem line 69

    Source documentation

    Degree-one multiplication raises the count, with square-zero products vanishing.

    theorem ideal_smul_mem (hN : ∀ (x : X) (v : N), (inr x : (TrivSqZeroExt D X)) • v = 0)
        {n r : ℕ} (x : X) {v : term k (TrivSqZeroExt D X) N n}
        (hv : v ∈ weight k D X N n r) :
        (inr x : (TrivSqZeroExt D X)) • v ∈ weight k D X N n (r+1) := by
    …

    Mentions: OAI.DerivedBar.term, OAI.DerivedBar.SquareZero.weight

  8. theorem OAI.DerivedBar.SquareZero.differential_mem line 90

    Source documentation

    Every face of the augmented algebra bar differential preserves the X-count.

    theorem differential_mem (hN : ∀ (x : X) (v : N), (inr x : (TrivSqZeroExt D X)) • v = 0)
        (n r : ℕ) {v : term k (TrivSqZeroExt D X) N (n+1)} (hv : v ∈ weight k D X N (n+1) r) :
        differential k (TrivSqZeroExt D X) N n v ∈ weight k D X N n r := by
    …

    Mentions: OAI.DerivedBar.term, OAI.DerivedBar.SquareZero.weight, OAI.DerivedBar.differential

  9. def OAI.DerivedBar.SquareZero.weightComplex line 124

    Source documentation

    The actual complex formed by the fixed-count homogeneous bar subspaces.

    def weightComplex (hN : ∀ (x : X) (v : N), (inr x : (TrivSqZeroExt D X)) • v = 0) (r : ℕ) :
        ChainComplex (ModuleCat k) ℕ :=
    …