Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!erhoogerbeet From: erhoogerbeet@watmath.UUCP Newsgroups: comp.ai Subject: In layman's terms. Message-ID: <13263@watmath.UUCP> Date: Fri, 22-May-87 18:50:15 EDT Article-I.D.: watmath.13263 Posted: Fri May 22 18:50:15 1987 Date-Received: Sat, 23-May-87 04:46:34 EDT Reply-To: erhoogerbeet@watmath.UUCP (Edwin (Deepthot)) Organization: U. of Waterloo, Ontario Lines: 51 Keywords: English, Backus-Naur Form, syntax. Summary: A request for a simplified overview. Hello. I am an undergrad going into computer science, and have long been interested in ai. But ai has always been "above" us lowly first and second year students and we have been relegated to the quicksorts and recursive n factorial problems. I think this would be a good place to have articles that introduced the laymen to ai to keep our interest. Recently, we worked on a simple compiler for numerical expressions using pwap on cms which is similar to yacc on unix. We entered a modified Backus-Naur Form and it spewed forth source code in pascal for an expression interpreter. Also, I have played many an adventure game and have always been intrigued by the way it parses and interprets commands given to it in simple English. Is there a Backus-Naur Form for the English language itself or is this too complicated? If not, how is it that we can understand a huge variety of different sentence forms and still recognize that some are syntactically incorrect? Basically, what I am asking is it possible to do syntactic checking as if "compiling" a sentence with rules set down in some BNF? As I understand it so far, natural language processing would have at least two levels (syntactic, semantic) and that syntactic checking level would be the basis of the other. "I bed he not on." is not syntactically or semantically correct. "Colourless green ideas sleep furiously." syntactically but not semantically correct. To be semantically correct, a sentence must be syntactically correct. Semantic checking would involve some connotation checking using trees and associations, but there is probably no clear-cut way of doing this. So I ask about syntactic checking. Some compilers have a front-end/back-end structure. Could syntactic checking be a front end part of the compiler? Theoretically, a syntax checker could be given a certain BNF for a language and be plugged into a back end semantic checker. But there must be someone out there on the net who can set me straight and do it in layman's terms. From an interested undergrad: ------ --------- ------------------------------------------ erhoogerbeet@watmath.uucp "`The Guide says there is an art to flying,' ehoogerbeets@wateuler.uucp said Ford,`or at least a knack. The knack lies Edwin (Deepthot) in learning how to throw yourself at the ground Hoogerbeets and miss.' He smiled weakly."