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D.6.20.5 is_ci
Procedure from library sing.lib (see sing_lib).
- Usage:
- is_ci(i); i ideal
- Return:
- intvec = sequence of dimensions of ideals (j[1],...,j[k]), for
k=1,...,size(j), where j is minimal base of i. i is a complete
intersection if last number equals nvars-size(i)
- Note:
- dim(0-ideal) = -1. You may first apply simplify(i,10); in order to
delete zeroes and multiples from set of generators
printlevel >=0: display comments (default)
Example:
| LIB "sing.lib";
int p = printlevel;
printlevel = 1; // display comments
ring r = 32003,(x,y,z),ds;
ideal i = x4+y5+z6,xyz,yx2+xz2+zy7;
is_ci(i);
==> // complete intersection of dim 0
==> // dim-sequence:
==> 2,1,0
i = xy,yz;
is_ci(i);
==> // no complete intersection
==> // dim-sequence:
==> 2,2
printlevel = p;
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