| 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); setring A; // this algebra is U(sl_2)
// PBW Basis of A_2 \ A_1 - monomials of degree == 2:
PBW_eqDeg( 2 );
==> _[1]=h2
==> _[2]=fh
==> _[3]=f2
==> _[4]=eh
==> _[5]=ef
==> _[6]=e2
|