Re: Why are some minus signs not cancelled?

Bill Allombert on Sun, 04 Aug 2013 15:09:15 +0200

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Re: Why are some minus signs not cancelled?

To: pari-users@pari.math.u-bordeaux.fr
Subject: Re: Why are some minus signs not cancelled?
From: Bill Allombert <Bill.Allombert@math.u-bordeaux1.fr>
Date: Sun, 4 Aug 2013 15:09:03 +0200
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On Sun, Aug 04, 2013 at 07:20:17AM +0200, Dirk Laurie wrote:
> Why does Pari/GP simplify -1/-2 to 1/2 but not -1/-x to 1/x?

1/2 is a t_FRAC which has a normal form.

-1/-x is a t_RFRAC which does not have a normal form in general, or at
least this is expensive to compute, so PARI does not attempt to do it.

Cheers,
Bill.

References:
- Why are some minus signs not cancelled?
  - From: Dirk Laurie <dirk.laurie@gmail.com>

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