restriction on sum: intentional bug?

[Terry Reedy]

Alan G Isaac wrote:
>
> As Tim explained in detail, and as Peter
> explained with brevity, whether it will
> happen or not, it should happen.  This
> conversation has confirmed that current
> behavior is a wart: an error is raised
> despite correct semantics. Ugly!

The fact that two or three people who agree on something agree on the 
thing that they agree on confirms nothing. One could just as well argue 
that summing anything but numbers is semantically incoherent, not 
correct. Certainly, my dictionary points in that direction.

tjr