Adding Unicode operators to D [use cases]

[Sergey Gromov]

Don wrote:
> If you could completely ignore keyboard and display issues, and use any
> unicode character as an operator, which ones would you actually use?

I'd use dot "⋅" and cross "×" products for 3D, union "∪" and
intersection "∩", subset "⊂" and superset "⊃" and their negative forms.
 I don't think I'd use anything else.

Well, comparisons look better when converted into appropriate unicode.