An Efficient Enumeration Algorithm for Canonical Form Underspecified Semantic Representations

We give polynomial-time algorithms for satisfiability and enumeration of underspecified semantic representations in a canonical form. This canonical form brings several underspecification formalisms together into a uniform framework (Manshadi et al., 2008), so the algorithms can be applied to any underspecified representation that can be converted to this form. In particular, our algorithm can be applied to Canonical Form Minimal Recursion Semantics (CF-MRS). An efficient satisfiability and enumeration algorithm has been found for a subset of MRS (Niehren and Thater, 2003). This subset, however, is not broad enough to cover all the meaningful MRS structures occurring in practice. CF-MRS, on the other hand, provably covers all MRS structures generated by the MRS semantic composition process.