ideal
=
;
ring r=0,(x,y,z),dp; poly s1 = x2; poly s2 = y3; poly s3 = z; ideal i = s1, s2-s1, 0,s2*s3, s3^4; i; ==> i[1]=x2 ==> i[2]=y3-x2 ==> i[3]=0 ==> i[4]=y3z ==> i[5]=z4 size(i); ==> 4 ncols(i); ==> 5