-A. Make the subalgebra class work with any subalgebra (there's nothing
- special except a_regular_element() in there).
+0. Add tests for orthogonality in the Peirce decomposition.
1. Add CartesianProductEJA.
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().
+ argument to random_eja(). This would also allow us to potentially
+ pass a "size" of zero to the other constructors in random_eja() --
+ a code path that is basically untested right now.