Opened 14 years ago

Closed 13 years ago

std over coeff rings (with zero-divisors) for local orderings

Reported by: Owned by: seelisch seelisch minor 3-1-1 singular-kernel 3-1-0 std, local order, zero-divisor

Description

Here are two examples over Z/8 with two and three vars, resp. Both ovecompute a wrong GB. The correct one is - in both cases - {4x, 4y+3x2, x3, 2x2}. The first computation seems to do something with the highest corner (as the ideal is 0-dim) which is not correct over this ground ring. The second has an additional variable z, so that the ideal is no longer 0-dim. Still here, the computed basis is not complete, as 2x2 is still missing.

\$ ./Singular

SINGULAR / Development

A Computer Algebra System for Polynomial Computations / version 3-1-0

0<

by: G.-M. Greuel, G. Pfister, H. Schoenemann \ Mar 2009

FB Mathematik der Universitaet, D-67653 Kaiserslautern \ executing /home/seelisch/sandbox/Singular/LIB/.singularrc

ring r = (integer, 2, 3), (x, y), ds;

You are using coefficient rings which are not fields. Please note that only limited functionality is available for these coefficients. The following commands are meant to work: - basic polynomial arithmetic - std - lift - reduce

poly f = 4y + 3x2; poly g = 4x; ideal i = f, g; i = std(i); i;

i[1]=4x i[2]=4y

\$ ./Singular

SINGULAR / Development

A Computer Algebra System for Polynomial Computations / version 3-1-0

0<

by: G.-M. Greuel, G. Pfister, H. Schoenemann \ Mar 2009

FB Mathematik der Universitaet, D-67653 Kaiserslautern \ executing /home/seelisch/sandbox/Singular/LIB/.singularrc

ring r = (integer, 2, 3), (x, y, z), ds;

You are using coefficient rings which are not fields. Please note that only limited functionality is available for these coefficients. The following commands are meant to work: - basic polynomial arithmetic - std - lift - reduce

poly f = 4y + 3x2; poly g = 4x; ideal i = f, g; i = std(i); i;

i[1]=4x i[2]=4y+3x2 i[3]=x3

comment:1 Changed 13 years ago by wienand

Resolution: → fixed new → closed

Caused by wrong selection of completion function (mora was used). Only the bba function is prepared to handle coefficient rings. Fixed in [12415].

comment:2 Changed 21 months ago by Merziuziy

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