An Overview of a Theory of Syntactic Recognition for Natural Language
Assume that the syntax of natural language can be parsed by a left-to-right deterministic mechanism without facilities for parallelism or backup. It will be shown that this "determinism" hypothesis, explored within the context of the grammar of English, leads to a simple mechanism, a grammar interpreter, having the following properties: (a) Simple rules of grammar can be written for this interpreter which capture the generalizations behind various linguistic phenomena, despite the seeming difficulty of capturing such generalizations in the framework of a processing model for recognition. (b) The structure of the grammar rules cannot parse sentences which violate either of two constraints which Chomsky claims are linguistic universals. This result depends in part upon the computational use of Chomsky's notion of Annotated Surface Structure. (c) The grammar interpreter provides a simple explanation for the difficulty caused by "garden path" sentences, such as "The cotton clothing is made of grows in Mississippi". To the extent that these properties, all of which reflect deep properties of natural language, follow from the original hypothesis, they provide indirect evidence for the truth of this assumption. This memo is an abridged form of several topics discussed at length in [Marcus 77]; it does not discuss the mechanism used to parse noun phrases nor the kinds of interaction between syntax and semantics discussed in that work.