An analysis of clausal coordination using synchronous tree adjoining grammar
Chung–hye Han, Sara Williamson, Logan Born, Anoop Sarkar · Journal of Logic and Computation · 2018
This paper presents a novel analysis of clausal coordination with shared arguments using synchronous tree adjoining grammar (STAG), a pairing of a tree adjoining grammar (TAG) for syntax and a TAG for semantics. In clausal coordination, one or more arguments can be shared by the verbal predicates of the conjuncts, as in Sue likes and Kim hates Pete, where an object argument Pete is shared by likes and hates. As the predicate-argument structure must be represented within each predicative elementary tree in TAG, modelling argument sharing across clauses poses an interesting challenge for TAG. A widely adopted approach within the TAG literature at present is to employ the conjoin operation (Sakar and Joshi, 1996, Proceedings of COLING ’96, 610–615), a non-standard tree-composing operation in TAG. This operation applies across elementary trees to identify and merge the arguments from each clause, yielding a derivation structure in which the shared arguments are combined with multiple elementary trees and a derived tree in which the shared arguments are dominated by multiple verbal projections. In contrast, our STAG analysis pairs a syntactic elementary tree that participates in the derivation of clausal coordination with a semantic elementary tree that includes a |$\lambda$|-term to abstract over the shared argument. This allows the sharing of arguments in coordination to be instantiated in semantics, without being represented in syntax in the form of multiple dominance, utilizing only the standard TAG operations, substitution and adjoining.