for i = 0 to (Bitvector.length v)-1 do
if Bitvector.get v i then
let n = Naive_tree.by_preorder tree i in
let n1 = get_firstBling tree n Naive_tree.nil in
let n2 = Naive_tree.parent_of_first tree n1 in
if n2 != Naive_tree.nil then begin let j = Naive_tree.preorder tree n2 in
for i = 0 to (Bitvector.length v)-1 do
if Bitvector.get v i then
let n = Naive_tree.by_preorder tree i in
let n1 = get_firstBling tree n Naive_tree.nil in
let n2 = Naive_tree.parent_of_first tree n1 in
if n2 != Naive_tree.nil then begin let j = Naive_tree.preorder tree n2 in