Top
Back: Crep
Forward: PtoCrep
FastBack:
FastForward:
Up: grobcov_lib
Top: Singular Manual
Contents: Table of Contents
Index: Index
About: About this document

D.2.4.6 Prep

Procedure from library grobcov.lib (see grobcov_lib).

Usage:
Prep(N,M);
Input: ideal N (null ideal) (not necessarily radical nor maximal) ideal M (hole ideal) (not necessarily containing N)
RETURN: The canonical P-representation of the locally closed set V(N) \ V(M) Output: [ Comp_1, .. , Comp_s ] where
Comp_i=[p_i,[p_i1,..,p_is_i]]
NOTE: Operates in a ring R=Q[a] (a=parameters)
KEYWORDS: Locally closed set, Canoncial form
EXAMPLE: Prep; shows an example

Example:
 
LIB "grobcov.lib";
if(defined(Grobcov::@P)){kill Grobcov::@R; kill Grobcov::@P; kill Grobcov::@RP;}
short=0;
ring R=0,(x,y,z),lp;
ideal E=x*(x^2+y^2+z^2-25);
ideal N=x*(x-3),y-4;
Prep(E,N);
==> [1]:
==>    [1]:
==>       _[1]=x2+y2+z2-25
==>    [2]:
==>       [1]:
==>          _[1]=z
==>          _[2]=y-4
==>          _[3]=x-3
==>       [2]:
==>          _[1]=z-3
==>          _[2]=y-4
==>          _[3]=x
==>       [3]:
==>          _[1]=z+3
==>          _[2]=y-4
==>          _[3]=x
==> [2]:
==>    [1]:
==>       _[1]=x
==>    [2]:
==>       [1]:
==>          _[1]=y-4
==>          _[2]=x


Top Back: Crep Forward: PtoCrep FastBack: FastForward: Up: grobcov_lib Top: Singular Manual Contents: Table of Contents Index: Index About: About this document
            User manual for Singular version 4-0-3, 2016, generated by texi2html.