Problems with subs

[Tatiana Zolo]

We do not understand how subs works in some cases: we tried the
following
ginsh session

> p=x+1;
1+x
> subs(p,x==k-1);
k
> subs(p,x==x-1);
-1+x
> subs(p,x==x-2);
-1+x
> subs(p,x==x^2-1);
x^2
> subs(p,x==x^2);
1+x^2

so, apparently, subs is sometimes wrong. We couldn't find anything in
the
documentation to explain this fact.


Thank you very much. Best wishes


Alessandro Zaccagnini
Tatiana Zolo

purrs developers,
at the University of Parma, Italy