OAI/Algebra/DepthFive/ShiftedOccupation.lean

GitHub source file

8 declarations, 0 contain sorry, 0 declared as axioms

  1. def OAI.Problem335.ShiftedOccupation.signedSource line 12

    Source documentation

    The integer occupation after subtracting one path shift from another.

    def signedSource {ι σ : Type*} [DecidableEq σ]
        (M : ι × σ → ℕ) (sign : ι → ℤ) (p q : ι → σ) (x : ι × σ) : ℤ :=
    …
  2. def OAI.Problem335.ShiftedOccupation.source line 18

    Source documentation

    Conversion to natural occupations; exact whenever all signed entries are nonnegative.

    def source {ι σ : Type*} [DecidableEq σ]
        (M : ι × σ → ℕ) (sign : ι → ℤ) (p q : ι → σ) : ι × σ → ℕ :=
    …
  3. lemma OAI.Problem335.ShiftedOccupation.source_cast line 22
  4. lemma OAI.Problem335.ShiftedOccupation.source_unique line 28
  5. lemma OAI.Problem335.ShiftedOccupation.exists_source_iff line 38

    Source documentation

    Validity of the integer shift is exactly the existence of a natural source occupation.

    lemma exists_source_iff {ι σ : Type*} [DecidableEq σ]
        (M : ι × σ → ℕ) (sign : ι → ℤ) (p q : ι → σ) :
        (∃ N : ι × σ → ℕ, ∀ x, (N x : ℤ) = signedSource M sign p q x) ↔
          ∀ x, 0 ≤ signedSource M sign p q x := by
    …

    Mentions: OAI.Problem335.ShiftedOccupation.signedSource

  6. lemma OAI.Problem335.ShiftedOccupation.signedSource_layer_sum line 50

    Source documentation

    The two path contributions cancel in each layer, even before imposing validity.

    lemma signedSource_layer_sum {ι σ : Type*} [Fintype σ] [DecidableEq σ]
        (M : ι × σ → ℕ) (sign : ι → ℤ) (p q : ι → σ) (t : ι) :
        (∑ a : σ, signedSource M sign p q (t, a)) = ∑ a : σ, (M (t, a) : ℤ) := by
    …

    Mentions: OAI.Problem335.ShiftedOccupation.signedSource

  7. lemma OAI.Problem335.ShiftedOccupation.source_layer_sum line 56

    Source documentation

    Every layer total of a valid shifted natural occupation is unchanged.

    lemma source_layer_sum {ι σ : Type*} [Fintype σ] [DecidableEq σ]
        (M : ι × σ → ℕ) (sign : ι → ℤ) (p q : ι → σ)
        (h : ∀ x, 0 ≤ signedSource M sign p q x) (t : ι) :
        (∑ a : σ, source M sign p q (t, a)) = ∑ a : σ, M (t, a) := by
    …

    Mentions: OAI.Problem335.ShiftedOccupation.signedSource, OAI.Problem335.ShiftedOccupation.source

  8. lemma OAI.Problem335.ShiftedOccupation.source_layers_sum line 67

    Source documentation

    In particular, both bidegrees are preserved for any partition into whole layers.

    lemma source_layers_sum {ι σ : Type*} [Fintype σ] [DecidableEq σ]
        (M : ι × σ → ℕ) (sign : ι → ℤ) (p q : ι → σ)
        (h : ∀ x, 0 ≤ signedSource M sign p q x) (layers : Finset ι) :
        (∑ t ∈ layers, ∑ a : σ, source M sign p q (t, a)) =
          ∑ t ∈ layers, ∑ a : σ, M (t, a) := by
    …

    Mentions: OAI.Problem335.ShiftedOccupation.signedSource, OAI.Problem335.ShiftedOccupation.source