-5. In CartesianProductEJA we already know the multiplication table and
- inner product matrix. Refactor things until it's no longer
- necessary to duplicate that work.
-
-6. Figure out how to remove Unital() from subalgebras.
+5. The rational_algebra() stuff doesn't really belong in classes that
+ don't derive from RationalBasisEJA or its as-yet-nonexistent
+ element class.