DATR: A Language for Lexical Knowledge Representation

Irregular lexemes are standardly regular in some respect. Most are just like regular lexemes except that they deviate in one or two characteristics. What is needed is a natural way of saying \this lexeme is regular except for this property". One obvious approach is to use nonmonotonicity and inheritance machinery to capture such lexical irregularity (and subregularity), and much recent research into the design of representation languages for natural language lexicons has thus made use of nonmonotonic inheritance networks (or \semantic nets") as originally developed for more general representation purposes in Arti cial Intelligence. Daelemans et al. (1992) provide a rationale for, and an introduction to, this body of research and we will not rehearse the content of that paper here, nor review the work cited there 1 . DATR is a rather spartan nonmonotonic language for de ning inheritance networks with path/value equations. In keeping with its intendedly minimalist character, it lacks many of the constructs embodied either in general purpose