«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»
Z. Sheikh, and F. Sánchez-Martínez. Proceedings of the First International Workshop on Free/Open-Source Rule-Based Machine Translation, page 67--74. Alicante, Universidad de Alicante. Departamento de Lenguajes y Sistemas Informáticos, (2009)