Then the GIZA++ implementation (Och and Ney, 2003) of IBM Model 5 is used to generate the five best word/predicate alignments from the corpus of NL sentences each paired with the predicate sequence for its MR. After predicates are assigned to words using word alignment, for each alignment of a training example and its syntactic parse, a SAPT is generated for composing the correct MR using the processes discussed in Sections 3 and 4.
a semantic label is assigned to each internal node of each SAPT, so that the MRs of its children are composed correctly according to the MR for this example.