Representing the case "no result"



Harald Geyer wrote:
>
>
> I think this would unify all suggestions we had in this thread so far
> and it should be consistently extendable for inf/minf/und etc.
>   
  Even if we agree on this, all the possibilities for  operations on 
these things must be defined, and they are not obvious. :(



> Also it might help to implement some kind of nan-arithmetic.
>   
There are papers on this topic trying to make a consistent selection of 
definitions.
NaNs are, I think, real.  There could be  NaN+%i*NaN also :)

RJF