[GAP Forum] Compute Direct sum M:=M_1\oplus M_2 of modules and End(M) with GAP

[Bernhard Boehmler]

Dear GAP forum,

I am interested in computing End_A (M) for a finitely generated A-Module M.
Here, A is a finitely generated Algebra (which should not be assumed to be
necessarily an elementary algebra).

I tried the following example (thereby restricting the considerations to a
group algebra, which is in this special case an elementary algebra):

After having typed

k:=GF(3);;
G:=CyclicGroup(3);;
R:=GroupRing(k,G);;
f:=IsomorphismMatrixAlgebra(R);;
kG:=Image(f);;

in GAP, I would like to enter the kG-module M:=(kG) \oplus (k)
and compute End_{kG} (M) as a subalgebra of a full matrix algebra
with the aid of the GAP package MeatAxe (or other GAP-packages), but,
unfortunately, I wasn't able to find out, how to do that.

Therefore, I would be very thankful, if somebody was able to explain, how
to do this.

Thank you very much for your help.

Kind regards,
Bernhard Boehmler