... Proceedings of the 47th Annual Meeting of the ACL and the 4th IJCNLP of the AFNLP, pages 324–332,Suntec, Singapore, 2-7 August 2009.c2009 ACL and AFNLP1 2 3 1123{ }324X ... X a XdXbX a XbXd≺X a ≺ Xb≺ Xc≺ Xd≺ XeXd≺ X a ≺ Xb≺ Xc≺ XeXd ≺ ≺ ≺ ≺ d(Y, Y)326 ❄❳❳❳❳❳③✘✘✘✘✘✾❄❄ ❄ ❄X a ⇒ ... ∼) =ifλiifiλi˜e˜fPtrans(˜f|˜e) Ptrans(˜e|˜f)Plex(˜f|˜e) Plex(˜e|˜f)eD∗eD∗= P (D), D e.D = Xi, i ∈ 1 |D|325X a → X1, X1Xb→ X1 X2,...