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5.1.56 kbase
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Syntax:
kbase ( ideal_expression )
kbase ( module_expression )
kbase ( ideal_expression, int_expression)
kbase ( module_expression, int_expression)
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Type:
the same as the input type of the first argument
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Purpose:
with one argument:
computes a vector space basis (consisting of monomials)
of the quotient ring by the ideal,
resp. of a free module by the module, in case it is finite dimensional
and if the input is a standard basis with respect to the ring ordering.
If the input is not a standard basis, the leading terms of the input are
used and the result may have no meaning.
With two arguments: computes the part of a vector space basis of the
respective quotient with degree of the monomials equal to the
second argument. Here, the quotient does not need to be finite dimensional.
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Example:
| ring r=32003,(x,y,z),ds;
ideal i=x2,y2,z;
kbase(std(i));
→ _[1]=xy
→ _[2]=y
→ _[3]=x
→ _[4]=1
i=x2,y3,xyz; // quotient not finite dimensional
kbase(std(i),2);
→ _[1]=z2
→ _[2]=yz
→ _[3]=xz
→ _[4]=y2
→ _[5]=xy
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See
ideal;
module;
vdim.
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