|
 |
 |
 |
 |
 |
 |
 |
 |
 |
7.7.3.0. PBW_eqDeg
Procedure from librarycentral.lib (see central_lib).
- Usage:
- PBW_eqDeg(Deg); Deg int
- Purpose:
- Compute PBW elements of a given degree.
- Return:
- ideal consisting of found elements.
- Note:
- Unit is omitted. Weights are ignored!
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 |