On 9/7/2010 1:49 PM, Jean Pellegri wrote:
>
> Salut
>
> Maxima says :
>
> (%i) inf - inf;
>
> (%o) 0
>
> This is obviously incorrect
>
>
not if they are the SAME inf. e.g. limit(x-x,x,inf).
More seriously, what would you like to see? There are various
proposals, e.g.
here's one.
each use of inf is labeled. then inf[1]-inf[2] is different from
inf[1]-inf[1].
With interval arithmetic, you have similar problems. e.g. if -1<x<1
is represented by interval(-1,1),
what is interval(-1,1) - interval(-1,1)? maxima says zero, but it
should be interval(-2,2).
unless they are the SAME interval.
RJF