[PURRS-devel] [Fwd: Problem with subs]

-------- Original Message -------- Subject: Problem with subs Date: Thu, 28 Feb 2002 11:43:51 +0100 From: Tatiana Zolo zolo@cs.unipr.it Reply-To: ginac-list@zino.physik.uni-mainz.de To: "ginac-list@zino.physik.uni-mainz.de" ginac-list@zino.physik.uni-mainz.de CC: Alessandro Zaccagnini zaccagni@prmat.math.unipr.it

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