eja: add TODON'T use Cramer's rule.

[sage.d.git] / mjo / eja / TODO

diff --git a/mjo/eja/TODO b/mjo/eja/TODO
index 67f390ba24f06e6d0f419609ddb8654afd0a65bf..38aa85bfe7a5c5ecc4b97c880c05533e42b5ad69 100644 (file)
--- a/mjo/eja/TODO
+++ b/mjo/eja/TODO
@@ -1,3 +1,8 @@
+A. Add tests for orthogonality in the Peirce decomposition.
+
+B. Add support for a symmetric positive-definite bilinear form in
+   the JordanSpinEJA.
+
 1. Add CartesianProductEJA.
 
 2. Check the axioms in the constructor when check != False?
@@ -9,9 +14,9 @@
 5. Factor out the unit-norm basis (and operator symmetry) tests once
    all of the algebras pass.
 
-6. Create Element subclasses for the matrix EJAs, and then override
-   their characteristic_polynomial() method to create a new algebra
-   over the rationals (with a non-normalized basis). We can then
-   compute the charpoly quickly by passing the natural representation
-   of the given element into the new algebra and computing its charpoly
-   there. (Relies on the theory to ensure that the charpolys are equal.)
\ No newline at end of file
+6. Can we make the minimal and characteristic polynomial tests work
+   for trivial algebras, too? Then we wouldn't need the "nontrivial"
+   argument to random_eja().
+
+7. Solve the charpoly system with A_of_x.solve_right(x_powers[r])
+   rather than dumbass Cramer's rule.