This directory contains a simple implementation of a recognizer, parser and probabilistic parser for Tree Insertion Grammars (TIGs).

You need Perl (ver 5) to run these programs.

To download the scripts, shift click on the following links to save them to your directory. Look at the sample runs given below for how to run the programs.

ckytig_simple.pl -- Simplified CKY recognizer for TIGs in `Chomsky Normal Form'
ckytig.pl        -- CKY recognizer for TIGs
ckytig_parse.pl  -- CKY parser for TIGs
ckytig_prob.pl   -- CKY parser for Probabilistic TIGs: reports best parse
grammar.pl       -- A slightly more interesting grammar
grammar2.pl      -- Even more interesting grammar
grammar3.pl      -- Same grammar with empty input list
viewtree         -- Adwait Ratnaparkhi's tree viewer
huge_val.c       -- reports value of HUGE_VAL for a machine


A default simple grammar and input string is contained within the scripts.



Sample run:

% ckytig.pl
% ckytig_parse.pl | viewtree
% ckytig_prob.pl | viewtree




Alternatively, you can try these programs on more interesting
grammars:


For example:

% ckytig_parse.pl grammar.pl | viewtree
% ckytig_prob.pl grammar.pl | viewtree


Or try:

% ckytig_parse.pl grammar2.pl | viewtree
% ckytig_prob.pl grammar2.pl | viewtree



 
If you set the @input list in grammar.pl to
the empty list, you can enter sentences in the stdin of the program.


For example:

% ckytig_parse.pl grammar3.pl | viewtree
John plays soccer



Anoop Sarkar anoop at linc.cis.upenn.edu