#8098: solve_mod is horribly broken
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Reporter: was | Owner: AlexGhitza
Type: defect | Status: new
Priority: critical | Milestone: sage-4.3.2
Component: basic arithmetic | Keywords:
Author: | Upstream: N/A
Reviewer: | Merged:
Work_issues: |
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Comment(by rkirov):
I tried to chase down the bug but it seems the rabbit hole goes deeper
(all the way to multivariate singular polynomial evaluation).
{{{
sage: P.<x,y> = Zmod(3^2)[]
sage: f=P(x*x)
sage: f(3,0)
1
sage: P.<x,y> = Zmod(10)[]
sage: f=P(x*y)
sage: f(2,5)
1
}}}
I think the problem is in the __call__ method in
http://sagenb.org/src/libs/singular/polynomial.pyx/ but its all Cython
land there, so I can't do much. In any case seems that Singular is fine,
and something gets lost in the translation.
{{{
> ring R= (integer,9),(x,y),dp;
> poly f=x2;
> subst(f,x,3,y,0);
0
}}}
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/8098#comment:1>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
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