Dear Forum,
I entered some small p-groups as finitely presented groups and used
the function DimensionsLoewyFactors. For the first ones everything
seemed OK, but once I got the following:

gap> g:=Group(a,b,c);
Group( a, b, c )
gap> g.name:="g";
"g"
gap> g.relators:=[a^3,b^3,c^3,a*b*a^2*b^2,a*c*b*a^2*c^2,b*c*b^2*c^2];
[ a^3, b^3, c^3, a*b*a^2*b^2, a*c*b*a^2*c^2, b*c*b^2*c^2 ]
gap> Size(g);
27
gap> DimensionsLoewyFactors(g);
Error, This function will not work for finitely presented groups.
Please use 'OperationCosetsFpGroup' in order to construct
an isomorphic permutation group in
G.operations.ConjugacyClasses( G ) called from
ConjugacyClasses( G ) called from
G.operations.Agemo( G, p ) called from
AgemoAbove( L[i], C, p ) called from
G.operations.JenningsSeries( G ) called from
..
brk>

What happens here?

Furthermore, I got the same
> Please use 'OperationCosetsFpGroup' in order to construct
> an isomorphic permutation group
when trying to compute Centre or ConjugacyClasses of a finitely
presented group.
Could somebody send more information and/or examples?

Thanks a lot,
Thierry Dana-Picard.