-4. Factor out the unit-norm basis (and operator symmetry) tests once
- all of the algebras pass.
-
-5. Override inner_product(), _max_test_case_size(), et cetera in
- DirectSumEJA.
-
-6. Switch to QQ in *all* algebras for _charpoly_coefficients().
- This only works when we know that the basis can be rationalized...
- which is the case at least for the concrete EJAs we provide,
- but not in general.
-
-7. Pass already_echelonized (default: False) and echelon_basis
- (default: None) into the subalgebra constructor. The value of
- already_echelonized can be passed to V.span_of_basis() to save
- some time, and usinf e.g. FreeModule_submodule_with_basis_field
- we may somehow be able to pass the echelon basis straight in to
- save time.
-
- This may require supporting "basis" as a list of basis vectors
- (as opposed to superalgebra elements) in the subalgebra constructor.
+4. Conjecture: if x = (x1,x2), then det(x) = det(x1)det(x2). This
+ should be used to fix the fact that det(x) is monstrously slow in
+ Cartesian product algebras, and thus randomly in the doctests.