Alpha( G )
returns for a solvable group G a list whose i-th entry is the maximal derived length of groups <G> / ker(chi) for chi in Irr(<G>) with chi(1) at most the i-th irreducible degree of G.
The result is stored in the group record as G.alpha
.
Note that calling this function will cause the computation of factor groups of G, so it works efficiently only for AG groups.
gap> Alpha( Sl23 ); [ 1, 3, 3 ] gap> Alpha( S4 ); [ 1, 2, 3 ]
GAP 3.4.4