Brian and Vincent,
Thanks for explaining.

If I understand you correctly, the decision is that a>b should only be
used in the mathematical meaning. I have also learned (from Vincent I
think) that cmp(a,b) will be removed from python 3.  What I don't
understand then is how Sympy objects can be sorted?  If __lt__,
__gt___, etc. are overloaded to construct objects, and __cmp__ is
deprecated, what is the plan for canonical ordering?

Øyvind

On 31 Mar, 23:02, Vinzent Steinberg <[email protected]>
wrote:
> On Mar 30, 7:43 pm, Brian Granger <[email protected]> wrote:
>
> > The reason is that the __nonzero__ methods of different Relational
> > subclasses use the .compare method in different ways.  I didn't write
> > this code, BUT I seem to remember that many tests fail if you simply
> > have __nonzero__ return True.  I didn't investigate why, but my guess
> > is that this is used to order different Relationals in expressions.
>
> This is imho a bug that should be fixed. Such things should not be
> used for ordering, this is not a clean approach and this should also
> be fixed.
>
> Vinzent

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