In a phrase-based statistical translation <cite>(Koehn et al., 2003)</cite> , a bilingual text is decomposed as K phrase translation pairs (ē 1 ,fā 1 ), (ē 2 ,fā 2 ), ...: The input foreign sentence is segmented into phrasesf K 1 , mapped into corresponding Englishē K 1 , then, reordered to form the output English sentence according to a phrase alignment index mappingā.