Given the two child sequences s 1 a = c n 1 and s 2 b = c n 2 (a and b are the last children) where s rewrite the relation as: Note that D p satisfies the recursive relation: By means of the above relation, we can compute the child subsequences of two sequences s 1 and s 2 in O(p|s 1 ||s 2 |).
the worst case complexity of the SPTK is identical to PTK, i.e.