D.2.4.2 katsura
...............
Procedure from library poly.lib (see poly_lib).

Usage:
katsura([n]): n integer

Return:
katsura(n) : n-th katsura ideal of

(1) newly created and set ring (32003, x(0..n), dp), if
nvars(basering) < n

(2) basering, if nvars(basering) >= n

katsura() : katsura ideal of basering

Example:
LIB "poly.lib";
ring r; basering;
==> //   characteristic : 32003
==> //   number of vars : 3
==> //        block   1 : ordering dp
==> //                  : names    x y z 
==> //        block   2 : ordering C
katsura();
==> _[1]=x+2y+2z-1
==> _[2]=x2+2y2+2z2-x
==> _[3]=2xy+2yz-y
katsura(4); basering;
==> _[1]=x(0)+2*x(1)+2*x(2)+2*x(3)-1
==> _[2]=x(0)^2+2*x(1)^2+2*x(2)^2+2*x(3)^2-x(0)
==> _[3]=2*x(0)*x(1)+2*x(1)*x(2)+2*x(2)*x(3)-x(1)
==> _[4]=x(1)^2+2*x(0)*x(2)+2*x(1)*x(3)-x(2)
==> //   characteristic : 32003
==> //   number of vars : 5
==> //        block   1 : ordering dp
==> //                  : names    x(0) x(1) x(2) x(3) x(4) 
==> //        block   2 : ordering C

<font size="-1">
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; User manual for <a href="http://www.singular.uni-kl.de/"><i>Singular</i></a> version 2-0-4, October 2002,
generated by <a href="http://www.gnu.org/software/texinfo/"><i>texi2html</i></a>.
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