|
InstallGlobalFunction(FirstStep,function(M,p)
local I,L,RC;
# Returns the first step of the projective resolution of M.
# Not thoroughly tested in the case that M is not
# the trivial G-module, but works in principle.
I:=IdentityMat(MTX.Dimension(M),MTX.Field(M));
L:=List(MTX.Generators(M),x->x-I);
if M!.isMTXModule and Size(MTX.BasisRadical(M))>1 then
RC:=BaseOrthogonalSpaceMat(MTX.BasisRadical(M));
else
RC:=I;
fi;
return LiftHom(L,RC,p);
end
);
[ Dauer der Verarbeitung: 0.20 Sekunden
(vorverarbeitet)
]
|