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D.4.2.4 nselect
Procedure from library elim.lib (see elim_lib).
- Usage:
nselect(id,n[,m]); id a module or ideal, n, m integers
- Return:
generators of id not containing the variable n [up to m]
Example:
LIB "elim.lib"; ring r=0,(x,y,t,s,z),(c,dp); ideal i=x-y,y-z2,z-t3,s-x+y3; nselect(i,3); → _[1]=x-y → _[2]=-z2+y → _[3]=y3-x+s module m=i*(gen(1)+gen(2)); show(m); → // module, 4 generator(s) → [x-y,x-y] → [-z2+y,-z2+y] → [-t3+z,-t3+z] → [y3-x+s,y3-x+s] show(nselect(m,3,4)); → // module, 2 generator(s) → [x-y,x-y] → [-z2+y,-z2+y] |