“…Continuing on, we obtain a tree that is not necessarily alphabetical, but which has the same lengths as an alphabetic tree which can be easily reconstructed (optimally) solving the problem (for a > 1). However, consider again a = 0.6, this time for weights (8,1,9,6,2). The Hu-Kleitman-Tamaki method first combines 6 and 2, then 8 and 1, then the first combined node with 9, and finally the remaining two nodes, resulting in a tree with lengths l = (2, 2, 2, 3, 3) and L a (w, l ) ≈ −4.121.…”