[net.ai] Seeking PD parser for simple English sentences.

heins@orion.UUCP (Michael Heins) (10/26/86)

[]
I am looking for public domain software which I can use to help me parse
simple English sentences into some kind of standardized representation.
I guess what I am looking for would be a kind of sentence diagrammer
which would not have to have any deep knowledge of the meanings of the
nouns, verbs, adjectives, etc.

The application is for a command interface to a computer, for use by
novice users.  C routines would be ideal.  Also, references to published
algorithms would be useful.  Thanks in advance.

-- 
	...!hplabs!sdcrdcf!trwrb!orion!heins

	We are a way for the universe to know itself. -- Carl Sagan

michaelm@bcsaic.UUCP (Michael Maxwell) (10/31/86)

In article <30@orion.UUCP> heins@orion.UUCP (Michael Heins) writes:
>I am looking for public domain software which I can use to help me parse
>simple English sentences into some kind of standardized representation.
>I guess what I am looking for would be a kind of sentence diagrammer
>which would not have to have any deep knowledge of the meanings of the
>nouns, verbs, adjectives, etc.
>
>...C routines would be ideal.  Also, references to published
>algorithms would be useful.

Since this seems to be a fairly common request, I am taking the liberty of
posting to the net...
Many Prologs (but not Turbo) have a built-in parser called `Definite Clause
Grammar' (DCG).  It is a way of writing phrase structure rules, which Prolog
then translates into standard Prolog rules.  Most standard texts on Prolog
discuss it, e.g.
%A W.F. Clocksin
%A C.S. Mellish
%D 1984
%T Programming in Prolog
%I Springer-Verlag
%C Berlin

A somewhat more sophisticated rule system was developed by Fernando Pereira in
his Ph.D. dissertation, published with some revision as:
%A Fernando Pereira
%D 1979
%T Extraposition Grammars
%R Working Paper No. 59
%I Department of Aritficial Intelligence, University of Edinburgh
%C Edinburgh

(You'd have to type the program in yourself; he includes a very simple
grammar of English.)

-- 
Mike Maxwell
Boeing Advanced Technology Center
	...uw-beaver!uw-june!bcsaic!michaelm