Dear GAP-forum, Dear Victor Bovdi, > Let A and B be finite 2-groups. > I am interested in the isomorphism classes of the semidirect (or/and > central) products of these groups. > > Do you know about a package which can aid this sort of calculation ?
There is no function that does these calculations directly -- you would have to go step-by-step in determining - Calculate Aut(N) (the package autpgrp will help) - Classify all homomorphisms from G to Aut(N) (there will be a function `AllHomomorphismClasses' in GAP4 and i can send you code for this privately if you are interested). - Form the semidirect products using `SemidirectProduct' - Test for isomorphism (the `anupq' package can help here, as the extensions are p-groups) Best wishes, Alexander Hulpke (with help from Bettina Eick) -- Colorado State University, Department of Mathematics, Weber Building, 1874 Campus Delivery, Fort Collins, CO 80523-1874, USA email: hul...@math.colostate.edu, Phone: ++1-970-4914288 http://www.math.colostate.edu/~hulpke _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum
