-7. Do we really need to orthonormalize the basis in a subalgebra?
- So long as we can decompose the operator (which is invariant
- under changes of basis), who cares?
+5. Compute the scalar in the general natural_inner_product() for
+ matrices, so no overrides are necessary. Actually, this is
+ probably better implemented as a dimension_over_reals() method
+ that returns 1, 2, or 4.
+
+6. The main EJA element constructor is happy to convert between
+ e.g. HadamardEJA(3) and JordanSpinEJA(3).