Looking over this again with a clear head, adding the number operators is the incorrect thing to do here I think, since that function was also written assuming we had a set-like view object as input.

I am inclined to think that the correct behavior here for those operators is to not change that function, but to not make values objects add-able at all, even with other values objects, which would probably be the only other logical choice,  so leaving that as it was before (but still making the equality change).