A rough sample of how to add ... (code below has not been compiled or determined to be syntactically correct.
Code:
SSELS = St0#st.ssels,
WeID = % YOU FIGURE IT OUT
MyAcc = fun(_Idx,Acc) ->
StrIdx = lists:flatten( io_lib:format("group_~p",[_Idx])),
SetVs =GetSet(_Idx, WeID), %% you must write this function
Key = {vertex,StrIdx},
Value = [{WeID, SetVs}]
gb_trees:enter((Key,Value,Acc),
end,
SSELS2 = lists:foldl(MyAcc, SSELS, lists:seq(1,100)),
St0#st{ssels=SSELS2}