Tree-adjoining Grammars for Optimality Theory Syntax

This paper explores an optimality-theoretic approach to syntax based on Tree-Adjoining Grammars (TAG), where two separate optimizations are responsible for the construction of local pieces of tree structure (elementary trees) and the combination of these pieces of structure. The local optimization takes a non-recursive predicate-argument structure (PA-chunk) as an underlying representation and chooses the best tree structure realizing it. The linking optimization takes as an underlying representation a tree whose nodes are labeled by PA-chunks and chooses among a set of structurally isomorphic TAG derivation trees. We provide formal definitions of the OTAG system and prove equivalence in strong generative capacity between OTAG and TAG. Finally, we apply the mechanics of the formal system to the analysis of cross-serial dependencies in Swiss-German.