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5.1.123 stdhilb
Procedure from library standard.lib (see standard_lib).
- Syntax:
stdhilb ( ideal_expression )
stdhilb ( ideal_expression, intvec_expression )
- Type:
- ideal
- Purpose:
- computes the standard basis of the homogeneous ideal in the basering,
via a Hilbert driven standard basis computation.
An optional second argument will be used as 1st Hilbert function.
- Assume:
- The optional second argument is the first Hilbert series as computed
by
hilb .
Example:
| ring r=0,(x,y,z),dp;
ideal i=y3+x2,x2y+x2,x3-x2,z4-x2-y;
ideal i1=stdhilb(i); i1;
==> i1[1]=y3+x2
==> i1[2]=x2y+x2
==> i1[3]=x3-x2
==> i1[4]=z4-x2-y
// the latter computation is equivalent to:
intvec v=hilb(i,1);
==> // ** i is no standardbasis
ideal i2=stdhilb(i,v); i2;
==> i2[1]=y3+x2
==> i2[2]=x2y+x2
==> i2[3]=x3-x2
==> i2[4]=z4-x2-y
| See also:
groebner;
std;
stdfglm.
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