LIB "tst.lib"; tst_init();
LIB "central.lib";
ring AA = 0,(e,f,h),dp;
matrix D[3][3]=0;
D[1,2]=-h;  D[1,3]=2*e;  D[2,3]=-2*f;
def A = nc_algebra(1,D); // this algebra is U(sl_2)
setring A;
// PBW Basis of A_2 - monomials of degree <= 2, without unit:
PBW_maxDeg( 2 );
tst_status(1);$