For the coordination structure analysis with alignment-based features we define the extended index set to be I ′ csa = I csa ∪ I uni where Here each triple (a, b, c) represents that word w c is recognized as the last word of the right conjunct and the scope of the left conjunct or the coordinating conjunction is w a ...w b 1 .
each parse-tree vector y will have additional components y a,b,c .