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7.5.1.0. inCentralizer
Procedure from library center.lib (see center_lib).
- Usage:
- inCentralizer(a, f); a poly/list/ideal, f poly
- Return:
- integer, 1 if a in the centralizer(f), 0 otherwise
- Purpose:
- check whether a given element is centralizing with respect to f
Example:
| LIB "center.lib";
ring r=0,(x,y,z),dp;
matrix D[3][3]=0;
D[1,2]=-z;
ncalgebra(1,D); // the Heisenberg algebra
poly f = x^2;
poly a = z; // we know this element if central
poly b = y^2;
inCentralizer(a, f);
==> 1
inCentralizer(b, f);
==> 0
list l = list(1, a);
inCentralizer(l, f);
==> 1
ideal I = a, b;
inCentralizer(I, f);
==> 0
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