Kaplan et al (1989) present an approach to machine translation based on co-description. In this paper we show that the notation is not as natural and expressive as it appears. We first show that the most natural analysis proposed in Kaplan et al (1989) cannot in fact cover the range of data for the important translational phenomenon in question. This contribution extends the work reported on in Sadler et al (1989) and Sadler et al (1990). We then go on to discuss alternatives which depart from or extend the formalism proposed in Kaplan et al (1989) in various.
