Paper: An Efficient Implementation Of PATR For Categorial Unification Grammar

ACL ID C90-2072
Title An Efficient Implementation Of PATR For Categorial Unification Grammar
Venue International Conference on Computational Linguistics
Session Main Conference
Year 1990
Authors
  • Todd Yampol (Stanford University, Stanford CA)
  • Lauri Karttunen (Palo Alto Research Center, Palo Alto CA; Stanford University, Stanford CA)

For example, a conjoined noun phrase, such as b and c, may require that the verb phrase it combines with has a list-valued semantic representation. If the verb phrase, such as are small, is not of that type, the unifier simply coerces the argument to a list value thereby producing two copies of its semantic translation. The algorithm for list unification is quite straightforward. (1) Two lists can be unified if they have the same number of elements, and if each corresponding pair of elements is unifiable. (2) Two lists of unequal lengths are not unifiable. (3) To unify a list of length n with a simple DG (non-list), coerce the nonlist into a list by making n copies of the nonlist, unifying each instance the non-list with a successive element of the list. (4) If any single sub-unification f...