LINK-GRAMMAR(1) 					      General Commands Manual						   LINK-GRAMMAR(1)

NAME

       link-parser - parses natural language sentences

SYNOPSIS

       link-parser [language] [-pp pp_knowledge_file] [-c constituent_knowledge_file] [-a affix_file] [-ppoff] [-coff] [-aoff] [-batch] [-<special
       "!" command>]

DESCRIPTION

       In Selator, D. and Temperly, D. "Parsing English with a Link Grammar" (1991), the authors defined a new formal grammatical system called  a
       "link grammar". A sequence of words is in the language of a link grammar if there is a way to draw "links" between words in such a way that
       the local requirements of each word are satisfied, the links do not cross, and the words form a consistent  connected  graph.  The  authors
       encoded English grammar into such a system, and wrote link-parser to parse English using this grammar.

       This  package can be used for linguistic parsing for information retrieval or extraction from natural language documents. Abiword also uses
       it as a grammar checker.

OPTIONS

       -pp pp_knowledge_file

       -c constituent_knowledge_file

       -a affix_file

       -ppoff

       -coff

       -aoff

       -batch

       -<special ! command>

USE

       link-parser, when invoked manually, will take control of the terminal; link-parser will then attempt to analyze the grammar of  all  input,
       unless escaped with an exclamation mark, according to the dictionary file provided as an argument. If escaped, the input will be treated as
       a "special command"; "!help" lists all special commands available.

       link-parser depends on a link-grammar dictionary which contains lists of words and associated metadata about their  grammatical	properties
       in  order to analyze sentences. A link-grammar dictionary provided by the authors of link-grammar is usually included with the link-grammar
       package, and can often be found somewhere in the /usr/share/link-grammar/ hierarchy. When this is the case, only  the  two-letter  language
       code  needs  to be specified on the command-line.  Alternatively, a user can provide their own dictionary as an argument, in which case the
       dictionary's directory should be specified. Hence, either of the commands

       link-parser en

       link-parser /usr/share/link-grammar/en
	      will run link-parser using the english dictionary included with the parser.

       While in a link-parser session, some example output could be:

	      linkparser> Reading a man page is informative.

	      ++++Time						0.00 seconds (0.01 total)

	      Found 1 linkage (1 had no P.P. violations)
		Unique linkage, cost vector = (UNUSED=0 DIS=0 AND=0 LEN=12)

		  +------------------------Xp-----------------------+
		  |	    +---------Ss*g---------+		    |
		  |	    +-------Os-------+	   |		    |
		  |	    |	  +----Ds----+	   |		    |
		  +----Wd---+	  |   +--AN--+	   +---Pa---+	    |
		  |	    |	  |   |      |	   |	    |	    |

	      LEFT-WALL reading.g a man.n page.n is.v informative.a .

       A P.P. violation is a post-processing violation; it is a post-linkage step used to reject invalid parses. The link types shown are specific
       to English; other langauges will have different link types.

       link-parser  can  also  be  used  non-interactively,  either  through its API, or via the -batch option.  When used with the -batch option,
       link-parser passively receives input from standard input, and when the stream finishes, it then outputs its analysis.  So  one  could  con-
       struct an ad-hoc grammar checker by piping text through link-parser with a batch option, and seeing what sentences fail to parse as valid:
	      cat thesis.txt | link-parser /usr/share/link-grammar/en/4.0.dict -batch

SEE ALSO

       Information   on   the	shared-library	 API   and  the  link  types  used  in	the  parse  is	avavailable  at  the  Abiword  website	at
       http://www.abisource.com/projects/link-grammar/dict/index.html
       Peer-reviewed papers explaining link-parser can be found at the original CMU site at http://www.link.cs.cmu.edu/link/papers/index.html.

AUTHOR

       link-parser was written by  Daniel  Sleator  <sleator@cs.cmu.edu>,  Davy  Temperley  <dtemp@theory.esm.rochester.edu>,  and  John  Lafferty
       <lafferty@cs.cmu.edu>

       This manual page was written by Ken Bloom <kbloom@gmail.com>, for the Debian project (but may be used by others).

								  April 18, 2008						   LINK-GRAMMAR(1)