The SD representation proved useful in a range of downstream tasks, including Textual Entailments (Dagan et al., 2006) and BioNLP (Fundel and Zimmer., 2007), and in recent years SD structures have also become a defacto standard for parser evaluation in English (de Marneffe and Manning, 2008a;Cer et al., 2010;Nivre et al., 2010).
collapsed U-SD structures interpret func elements in order to refine the representation of relations between content words.