Multi-Tape Two-Level Morphology: A Case Study in Semitic Non-linear   Morphology
  This paper presents an implemented multi-tape two-level model capable of describing Semitic non-linear morphology. The computational framework behind the current work is motivated by Kay (1987); the formalism presented here is an extension to the formalism reported by Pulman and Hepple (1993). The objectives of the current work are: to stay as close as possible, in spirit, to standard two-level morphology, to stay close to the linguistic description of Semitic stems, and to present a model which can be used with ease by the Semitist. The paper illustrates that if finite-state transducers (FSTs) in a standard two-level morphology model are replaced with multi-tape auxiliary versions (AFSTs), one can account for Semitic root-and-pattern morphology using high level notation. 
George Kiraz (University of Cambridge)