Mihail,
As Rupert says, you can *change* the canonical ordering.
However, the only way to turn it off is to turn off simplification entirely
(with simp:false), which is almost never a good idea. Maxima's sorting of
variables is a central part of its simplification system. Without it, x+y-x
will remain as x+y-x, and most parts of Maxima will not work properly.
-s
On Fri, Feb 12, 2010 at 7:08 AM, Rupert Swarbrick <rswarbrick at googlemail.com
> wrote:
> Mihail Denisenko <mihail22 at nigma.ru> writes:
> > I have a question about simplification system. Usually Maxima does
> sorting
> > of all variable-names in result of processing.
> >
> > For example, for input x+y we will have output y+x.
> >
> > Is it possible to suppress this behavior of Maxima? Is it necessary to do
> > changes in the source code of simplification system?
>
> You might want to have a look at ordergreat and orderless, which changes
> the canonical ordering. Also see the mainvar property. All of these are
> in section 6.8 of the manual: "Functions and Variables for Expressions".
>
> Rupert
>
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