... L¨u and Qun LiuKey Laboratory of Intelligent Information ProcessingInstitute of Computing TechnologyChinese Academy of SciencesP.O. Box 2704, Beijing 100190, China{yliu,lvyajuan,liuqun}@ict.ac.cnAbstractCurrent ... benefit of providing rules linguistically bet-ter motivated. However, while string -to- tree andtree -to- string models demonstrate promising re-sults in empirical evaluations, tree -to- tree modelshave ... originally de-veloped for the tree -to- string case, it is possible to extend GHKM to extract all valid tree -to- tree rulesfrom aligned packed forests. In this section, we introduce our tree -to- tree...