Top
Back: centralizer
Forward: inCentralizer
FastBack: PLURAL libraries
FastForward: involut_lib
Up: center_lib
Top: Singular Manual
Contents: Table of Contents
Index: Index
About: About this document
7.5.1.0. inCenter
Procedure from library center.lib (see center_lib).

Usage:
inCenter(a); a poly/list/ideal

Return:
integer, 1 if a in the center, 0 otherwise

Purpose:
check whether a given element is central

Example:
 
LIB "center.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 p=4*x*y+z^2-2*z;
inCenter(p);
==> 1
poly f=4*x*y;
inCenter(f);
==> 0
list l= list( 1, p, p^2, p^3);
inCenter(l);
==> 1
ideal I= p, f;
inCenter(I);
==> 0


Top Back: centralizer Forward: inCentralizer FastBack: PLURAL libraries FastForward: involut_lib Up: center_lib Top: Singular Manual Contents: Table of Contents Index: Index About: About this document
            User manual for Singular version 3-0-1, October 2005, generated by texi2html.