Top
Back: D.4.7.2 primdecGTZ
Forward: D.4.7.4 minAssGTZ
FastBack: Appendix D SINGULAR libraries
FastForward: E Release Notes
Up: D.4.7 primdec_lib
Top: 1 Preface
Contents: Table of Contents
Index: F Index
About: About This Document

D.4.7.3 primdecSY

Procedure from library primdec.lib (see primdec_lib).

Usage:

primdecSY(i); i ideal, c int

Return:

a list pr of primary ideals and their associated primes:

   pr[i][1]   the i-th primary component,
   pr[i][2]   the i-th prime component.
Note:

Algorithm of Shimoyama/Yokoyama.

   if c=0,  the given ordering of the variables is used,
   if c=1,  minAssChar tries to use an optimal ordering,
   if c=2,  minAssGTZ is used,
   if c=3,  minAssGTZ and facstd are used.

Example:

LIB "primdec.lib";
ring  r = 0,(x,y,z),lp;
poly  p = z2+1;
poly  q = z3+2;
ideal i = p*q^2,y-z2;
list pr = primdecSY(i);
pr;
→ [1]:
→    [1]:
→       _[1]=z6+4z3+4
→       _[2]=y-z2
→    [2]:
→       _[1]=z3+2
→       _[2]=y-z2
→ [2]:
→    [1]:
→       _[1]=z2+1
→       _[2]=y+1
→    [2]:
→       _[1]=z2+1
→       _[2]=y+1

Top Back: D.4.7.2 primdecGTZ Forward: D.4.7.4 minAssGTZ FastBack: Appendix D SINGULAR libraries FastForward: E Release Notes Up: D.4.7 primdec_lib Top: 1 Preface Contents: Table of Contents Index: F Index About: About This Document
            User manual for Singular version 2-0-4, October 2002, generated by texi2html.