-7. If we factor out a "matrix algebra" class, then it would make sense
- to replace the custom embedding/unembedding functions with static
- _real_embedding() and _real_unembedding() methods.
+5. Profile the construction of "large" matrix algebras (like the
+ 15-dimensional QuaternionHermitianAlgebra(3)) to find out why
+ they're so slow.