OAI/Analysis/AffineBernstein/PiolaAlgebra.lean

GitHub source file

6 declarations, 0 contain sorry, 0 declared as axioms

  1. def OAI.AffineBernstein.continuousDetRows line 13

    Source documentation

    The determinant, as a continuous map multilinear in its rows.

    def continuousDetRows : ContinuousMultilinearMap ℝ (fun _ : ι => ι → ℝ) ℝ :=
    …
  2. theorem OAI.AffineBernstein.continuousDetRows_apply line 18
  3. theorem OAI.AffineBernstein.det_updateRow_pair_swap line 22

    Source documentation

    Exchanging two independently replaced rows reverses the determinant.

    theorem det_updateRow_pair_swap (A : Matrix ι ι ℝ) {i l : ι} (hil : i ≠ l)
        (v w : ι → ℝ) :
        ((A.updateRow i v).updateRow l w).det =
          -((A.updateRow i w).updateRow l v).det := by
    …
  4. theorem OAI.AffineBernstein.det_updateRow_sum line 44

    Source documentation

    Expand one determinant row in the coordinate vectors.

    theorem det_updateRow_sum (A : Matrix ι ι ℝ) (l : ι) (v : ι → ℝ) :
        (A.updateRow l v).det = ∑ m, v m * (A.updateRow l (Pi.single m 1)).det := by
    …
  5. theorem OAI.AffineBernstein.sum_two_rows_eq_zero line 58

    Source documentation

    Symmetric coefficients contract to zero with an alternating pair of rows.

    theorem sum_two_rows_eq_zero (A : Matrix ι ι ℝ) {i l : ι} (hil : i ≠ l)
        (T : ι → ι → ℝ) (hT : ∀ j m, T j m = T m j) :
        (∑ j, ∑ m, T j m *
          ((A.updateRow i (Pi.single j 1)).updateRow l (Pi.single m 1)).det) = 0 := by
    …
  6. theorem OAI.AffineBernstein.piola_cancel line 80

    Source documentation

    The algebraic cancellation underlying the Piola identity.

    theorem piola_cancel (A : Matrix ι ι ℝ) (i : ι) (T : ι → ι → ι → ℝ)
        (hT : ∀ l j m, T l j m = T l m j) :
        (∑ j, ∑ l, ((A.updateRow i (Pi.single j 1)).updateRow l
          (if l = i then 0 else T l j)).det) = 0 := by
    …