### Underspecified computation of normal forms

Alexander Koller & Stefan Thater
We show how to compute readings of ambiguous natural language sentences that are minimal in some way. Formally, we consider the problem of computing, out of a set C of trees and a rewrite system R, those trees in C that cannot be rewritten into a tree in C. We solve the problem for sets of trees that are described by semantic representations typically used in computational linguistics, and a certain class of rewrite systems...