This may require supporting "basis" as a list of basis vectors
(as opposed to superalgebra elements) in the subalgebra constructor.
-7. Use charpoly for inverse stuff if it's cached.
-
-8. The inner product should be an *argument* to the main EJA
+7. The inner product should be an *argument* to the main EJA
constructor. Afterwards, the basis normalization step should be
optional (and enabled by default) for ALL algebras, since any
algebra can have a nonstandard inner-product and its basis can be