Home Online Manual
Top
Back: spmul
Forward: spsemicont
FastBack:
FastForward:
Up: gmssing_lib
Top: Singular Manual
Contents: Table of Contents
Index: Index
About: About this document

D.6.9.17 spissemicont

Procedure from library gmssing.lib (see gmssing_lib).

Usage:
spissemicont(sp[,1]); list sp, int opt

Return:
 
int k=
  1;  if sum of sp is positive on all intervals [a,a+1) [and (a,a+1)]
  0;  if sum of sp is negative on some interval [a,a+1) [or (a,a+1)]

Example:
 
LIB "gmssing.lib";
ring R=0,(x,y),ds;
list sp1=list(ideal(-1/2,-3/10,-1/10,0,1/10,3/10,1/2),intvec(1,2,2,1,2,2,1));
spprint(sp1);
==> (-1/2,1),(-3/10,2),(-1/10,2),(0,1),(1/10,2),(3/10,2),(1/2,1)
list sp2=list(ideal(-1/6,1/6),intvec(1,1));
spprint(sp2);
==> (-1/6,1),(1/6,1)
spissemicont(spsub(sp1,spmul(sp2,3)));
==> 1
spissemicont(spsub(sp1,spmul(sp2,4)));
==> 0