the nontrivial factor. On the other hand, it's nice that we can
test out some alternate code paths...
-4. Conjecture: if x = (x1,x2), then det(x) = det(x1)det(x2).
+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.