In order to separate out the individual contributions of the novel HD-HRs and NRRs, we carry out an additional experiment (HD-HR+Glue) using HD-HRs with monotonic glue rules only (adjusted to refined rule labels, but effectively switching off the extra reordering power of full NRRs).
examining translation rules extracted from the training data shows that there are 72,366 types of non-terminals with respect to 33 types of POS tags.