... unification. Therefore, any improvements in the efficiency of unification would have direct conse- quences for the overall performance of the sys- tem. One key to reducing the cost of unification ... Computing Sciences, University of Sussex Falmer, Brighton BN1 9QH, UK *Center for the Study of Language and Information, Stanford University Ventura Hall, Stanford, CA 94305-4115, USA {kiefer, ... fit in with the intuitions of the grammar-writers. In particular, some of the paths are very long (of length ten or more). Optimal sets of paths for grammars of this complexity could not...