Home Online Manual
Top
Back: NPos_test
Forward: NPos
FastBack:
FastForward:
Up: noether_lib
Top: Singular Manual
Contents: Table of Contents
Index: Index
About: About this document

D.4.24.2 modNpos_test

Procedure from library noether.lib (see noether_lib).

Usage:
modNpos_test(i); i an ideal

Return:
1 if i is in Noether position 0 otherwise.

Note:
This test is a probabilistic test, and it computes the initial of the ideal modulo the prime number 2147483647 (the biggest prime less than 2^31).

Example:
 
LIB "noether.lib";
ring r=0,(X,Y,a,b),dp;
poly f=X^8+a*Y^4-Y;
poly g=Y^8+b*X^4-X;
poly h=diff(f,X)*diff(g,Y)-diff(f,Y)*diff(g,X);
ideal i=f,g,h;
modNpos_test(i);
==> // WARNING:
==> // The procedure is probabilistic and  it computes the initial of the ide\
   al modulo the prime number 2147483647
==> [1]:
==>    0
==> [2]:
==>    [1]:
==>       X
==>    [2]:
==>       Y
==>    [3]:
==>       b
==>    [4]:
==>       a