 LIB "ncalg.lib";
def Usl2 = makeUsl2(); // this algebra is U(sl_2)
setring Usl2;
option(redSB);
option(redTail);
poly C = 4*e*f+h^22*h; // the central element of Usl2
ideal I = e^3,f^3,h^34*h;
ideal J = twostd(I);
// print a compact presentation of J:
print(matrix(ideal(J[1..5]))); // first 5 generators
==> h34h,fh22fh,eh2+2eh,f2h2f2,2efhh22h
print(matrix(ideal(J[6..size(J)]))); // last generators
==> e2h+2e2,f3,ef2fh,e2feh2e,e3
ideal QC = twostd(C8);
qring Q = QC;
ideal QJ = fetch(Usl2,J);
QJ = std(QJ);
// thus QJ is the image of I in the factoralgebra QC
print(matrix(QJ)); // print QJ compactly
==> h34h,fh22fh,eh2+2eh,f2h2f2,e2h+2e2,f3,e3
