Based on a similar definition of partial parse, <cite>Zhang et al. (2007a)</cite> formulated the following statistical model: <cite>The above model</cite> contains two probabilistic components: i) P (Ω|w) is the conditional probability of a segmentation Ω given the input sequence w; and ii) P (t i |w i ) is the conditional probability of an analysis t i for a given subsequence w i in the segmentation.