According to the independence assumption in Equation 2, with the addition of prosodic edge X → b j , the same sub-tree also has the highest probability, denoted by P (i, j, X, 1), of generating word sequence w j i together with the break index sequence b j i .
we have: The structural constraint that a break index is only generated by the highest nonterminal that covers the preceding word as the right-most terminal enables a dynamic programming algorithm to compute P (i, j, X, 0) and thus P (i, j, X, 1) efficiently.