#162 closed bug (fixed)
std over coeff rings (with zero-divisors) for local orderings
Reported by: | seelisch | Owned by: | seelisch |
---|---|---|---|
Priority: | minor | Milestone: | 3-1-1 |
Component: | singular-kernel | Version: | 3-1-0 |
Keywords: | std, local order, zero-divisor | Cc: |
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;
$ ./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;
Caused by wrong selection of completion function (mora was used). Only the bba function is prepared to handle coefficient rings. Fixed in [12415].