From: Alexei Sheplyakov <alexei.sheplyakov@gmail.com>
Date: Mon, 17 May 2010 22:23:03 +0000 (+0200)
Subject: pgcd(), chinrem_gcd(): use appropriate definition of the degree.
X-Git-Tag: release_1-5-8~6
X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=commitdiff_plain;h=edf1ae46a926d0a718063c149b78c1b9a7ec2043;hp=edf1ae46a926d0a718063c149b78c1b9a7ec2043

pgcd(), chinrem_gcd(): use appropriate definition of the degree.

Effect: fixes (rare) GCD miscalculation.

pgcd() treats polynomials Z_p[x_0, ..., x_n] as R[x_0, ..., x_{n - 1}], where
R = Z_p[x_n]. Therefore one should use correct definition of the degree
(i.e. compute it w.r.t. x_0, ..., x_{n-1}, but NOT w.r.t. x_n!).

One should use appropriate definition of degree (that is, w.r.t.  x_0, ..., x_n)
in chinrem_gcd() too.

Thanks to Aless Lasaruk for a bug report.
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