-1. Add CartesianProductEJA.
+1. Add references and start citing them.
-2. Add references and start citing them.
+2. Profile (and fix?) any remaining slow operations.
-3. Implement the octonion simple EJA.
+3. When we take a Cartesian product involving a trivial algebra, we
+ could easily cache the identity and charpoly coefficients using
+ the nontrivial factor. On the other hand, it's nice that we can
+ test out some alternate code paths...
-4. Factor out the unit-norm basis (and operator symmetry) tests once
- all of the algebras pass.
+4. Add dimension bounds on any tests over AA that compute element
+ subalgebras.
-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.
-
-8. Implement random_instance() for general algebras as random_eja().
- Copy/paste the "general" construction into the other classes that
- can use it. The general construction can be something like "call
- random_instance() on something that inherits me and return the
- result."
-
-9. Pre-cache the one() method for concrete algebras, and test the general
- method by clearing the cache.
+5. The rational_algebra() stuff doesn't really belong in classes that
+ don't derive from RationalBasisEJA or its as-yet-nonexistent
+ element class.