«takes as input a sequence of phrase-structure trees and modifies their labels according to a set of rules. ... Its rule notation is flexible enough to emulate head/argument-finding rules»
D. Marcu, and W. Wong. EMNLP '02: Proceedings of the ACL-02 conference on Empirical methods in natural language processing, page 133--139. Morristown, NJ, USA, Association for Computational Linguistics, (2002)