let compose_assocs_post assocs_st (post_st,post_tr) =
let st,tr = mk_empty_pre_or_post () in
let st,tr = ref st, ref tr in
Array.iteri
(fun index b ->
if b then begin
st:=bool_array_or post_st.(index) !st;
tr:=bool_array_or post_tr.(index) !tr
end
)
assocs_st;
(!st,!tr)