-7. Drop the element-subalgebra in favor of a regular subalgebra. The
- cached "one" can be set in the method.
+6. We should compute whether or not the algebra is associative if it
+ is unknown. I guess the "associative" argument should be ternary
+ (True, False, None)? We should also figure out the correct
+ True/False values for the example classes, and of course add an
+ _is_associative() method.
+
+7. Set check_axioms=False for element-subalgebras outside of once or
+ twice in the test suite.