Such syntax-based SMT systems can automatically extract larger rules, and learn syntactic reorderings for translation (Yamada and Knight, 2001;Venugopal and Zollmann, 2006;Galley et al., 2004;Chiang, 2007;Zollmann et al., 2008;DeNero et al., 2009;Shen et al., 2010;Genzel, 2010).
many problems remain unsolved.