D.5.9.8 posweight
.................
Procedure from library spcurve.lib (see spcurve_lib).

Usage:
posweight(M,t1,n[,s]); M matrix, t1 module, n int, s string 

n=0 : all deformations of non-negative weight 

n=1 : only non-constant deformations of non-negative weight 

n=2 : all deformations of positive weight 

As an optional parameter the name of a new ring may be
specified.

Assume:
M is a presentation matrix of a Cohen-Macaulay codimension 2
ideal and t1 is its T1 space in matrix notation

Create:
new basering (default name: rneu); a different name for this ring
may be given as a 4th parameter

Return:
list, consisting of a presentation matrix describing the deformation
given by the generators of T1 of non-negative/positive weight
and the weight vector for the new variables

Note:
The current basering should not contain any variables named
T(i) where i is some integer!

Example:
LIB "spcurve.lib";
ring r=32003,(x(1),x(2),x(3)),ds;
ideal curve=(x(3)-x(1)^2)*x(3),(x(3)-x(1)^2)*x(2),x(2)^2-x(1)^7*x(3);
matrix M=isCMcod2(curve);
list l=matrixT1(M,3);
list li=posweight(l[1],std(l[2]),0);
pmat(li[1]);
==> T(2)+x(1)*T(1), -x(3)+x(1)^2, 
==> -x(3),          x(2),         
==> x(2),           -x(1)^7
li[2];
==> 3,1

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&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; User manual for <a href="http://www.singular.uni-kl.de/"><i>Singular</i></a> version 2-0-4, October 2002,
generated by <a href="http://www.gnu.org/software/texinfo/"><i>texi2html</i></a>.
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