-4. Can we hit "x" with the deortho matrix and delegate to the
- _rational_algebra to speed up minimal_polynomial?
+4. Add dimension bounds on any tests over AA that compute element
+ subalgebras.
+
+5. The rational_algebra() stuff doesn't really belong in classes that
+ don't dervice from RationalBasisEJA or its as-yet-nonexistent
+ element class.