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B.7.0.12 IsCentral
Procedure from library nctools.lib (see nctools_lib).
- Usage:
- IsCentral(p,[v]); p poly, v an integer (with v!=0 procedure will be verbose)
- Return:
- integer (1 if p commutes with all variables, 0 otherwise)
Example:
| LIB "nctools.lib";
ring r=0,(x,y,z),dp;
matrix D[3][3]=0;
D[1,2]=-z;
D[1,3]=2*x;
D[2,3]=-2*y;
ncalgebra(1,D); // this is U(sl_2)
poly c = 4*x*y+z^2-2*z;
IsCentral(c,0);
==> 1
poly h = x*c;
IsCentral(h,1);
==> Noncentral at: y
==> Noncentral at: z
==> 0
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