Reversible grammars and natural language processing

In general terms, if(1) describes the task of getting from point A to point B then (2) deseribes the task of getting from @nt B to point A. A natural question to ask is whether the same code can be used to achieve both goals, somehow being run in different dKections. In what follows we will Ftrat argue that this bidwectional mapping function should be a part of any natural language processing model. Second, we provide further defiition for the goal we seek to achieve by fixing on details of the representations we are mapping between as well as details of the transformation process. Concerning the latter issue we contrast the current endeavor with that of Strzatkowski 1990, this being perhaps the most similar effort described in the literature, Third we provide details of a bidirectional implementation for various kinds of noun phrases in English. Finally, we discuss the implications of adopting the bidirectional grammar hypothesis and discuss future directions.