Code review comment for lp:~fluidity-core/fluidity/firedrake-mixed-space-expressions

So, foo**bar doesn't work at all for mixed spaces. This is the same as dolfin. I think it would be possible to make it work, but I'm not sure if it actually makes sense. The error is deep in UFL.

The component tensor error I think needs one to unpick more UFL classes.

The other option is to lie about the ufl_element in the mixed function spaces. If I say that

fs._ufl_element = self._function_spaces[0]._ufl_element then everything works. But that's tremendously icky.