From 47bd4f2f3bf0dce7e4d29539716f431eea6a0b14 Mon Sep 17 00:00:00 2001 From: Max Horn Date: Tue, 5 Jun 2018 17:23:18 +0100 Subject: [PATCH] Remove NilpotentQuotient for fp-groups Under normal circumstances, these are never triggered, and a normal user has no good way to ever use them. On the other hand, a pro user can easily get the same effect by replicating what these methods do. So all in all, there seems to be no point in having these methods. In practice, though, due to a fundamental issue with GAP method ranking, it can happen that lpres' NilpotentQuotient methods for fp-groups actually *do* end up being ranked higher than the methods from nq, and I'd argue this is undesirable in general. For details, see --- gap/nq.gi | 16 ---------------- 1 file changed, 16 deletions(-) diff --git a/gap/nq.gi b/gap/nq.gi index ec40029..b4411c6 100644 --- a/gap/nq.gi +++ b/gap/nq.gi @@ -521,22 +521,6 @@ InstallMethod( NilpotentQuotients, return( List([1..c], i -> NqEpimorphismNilpotentQuotient(G,i) ) ); end); -############################################################################ -## -#M NilpotentQuotient( ) -## -InstallOtherMethod( NilpotentQuotient, - "for an FpGroup using the LPRES-package", true, - [ IsFpGroup, IsPosInt ], -1, # give priority to NQ package - function( G, c ) - return( NilpotentQuotient( Range( IsomorphismLpGroup( G ) ), c ) ); - end); - -InstallOtherMethod( NilpotentQuotient, - "for an FpGroup using the LPRES-package", true, - [ IsFpGroup ], -1, # give priority to NQ package - G -> NilpotentQuotient( Range( IsomorphismLpGroup( G ) ) ) ); - ############################################################################ ## #M NqEpimorphismNilpotentQuotient( )