AspCcgTk

This page is about AspCcgTk - the Answer Set Programming Combinatory Categorial Grammar Toolkit. AspCcgTk is a parser based on Combinatory Categorial Grammar (CGC) developed using declarative programming paradigm -- Answer Set Programming. It implements wide-coverage CCG parsing by utilizing the CCG postagger and supertagger of the C&C tool. AspCcgTk aims at producing all semantically distinct parse trees for a given sentence. Compared to typical approaches to CCG parsing, no parsing algorithm is implemented within this tool. Instead, the task of CCG parsing is formulated as a planning problem and answer set programming systems are used to compute solutions that correspond to valid parses. AspCcgTk can also be seen as a basis for a generic tool for encoding different CCG category and rule sets in a declarative and straightforward manner. In other words, AspCcgTk provides a test-bed for experimenting with different theoretical CCG frameworks without the need to craft specific parsing algorithms. AspCcgTk also contains a module for visualizing CCG derivations found by a parser.

Table of Contents

• Download (single files)
• Download (full toolkit package)
• How to use the package
• Example Visualizations
• Publication
• Third Party Software Used
• Authors

Download (single files)

If you want to have a look at parts of the encoding, you find some direct download links here:

• Core ASP encoding of the CCG parser: ccg.asp.
• ASP encoding for visualizing answer sets of ccg.asp using IDPDraw: ccg2idpdraw.asp.
  (Note that the answer set of ccg2idpdraw.asp are preprocessed by aspccgtk.py to create human readable CCG category labels from function symbols.)
• Main AspCcgTk python toolkit file for parsing and displaying: parse_and_display.py.
• AspCcgTk python toolkit file for supertagging using C&C (creates input for parse_and_display.py): supertag.py.
• Example ASP input using a dictionary:
  The dog bit John.
  • encoding of sentence: the_dog_bitjohn.asp,
  • encoding of dictionary: common_dict.asp.
• Example ASP input for supertagged sentence from CCGBank: ccgbanksample1.asp. The sentence is
  More than a few CEOs say the treatment tempts them to return to a heartland city for future meetings.
• The README file for the aspccgtk package: README.

Download (full toolkit package)

If you want to play around with AspCcgTk, please download the full package containing all related libraries and other tools (IDPDraw has been patched to display strings, BioASP has been extended for better parsing and optimization capabilities).

Full package downloads:

• aspccgtk-0.2.tar.gz February 2012 (66MB, contains IDPDraw, BioASP and C&C including statistical models)
• aspccgtk-0.1.tar.gz July 2011 (deprecated version)

How to use the package

Please have a look at the README file which contains step-by-step instructions for building IDPDraw and experimenting with AspCcgTk: README.

Example visualizations

Single derivation:

Derivation 1:

Derivation 2:

Derivation 3:

Publication

Parsing Combinatory Categorial Grammar with Answer Set Programming: Preliminary Report (PDF), Yuliya Lierler and Peter Schueller, 25th Workshop on Logic Programming (WLP), (2011)

Third Party Software Used

AspCcgTk uses the following libraries and/or tools developed by others:

• scripting language python
• CCG postagger and supertagger C&C
• ASP grounder and solver gringo and clasp
• python library BioASP (available from the potassco repository)
• answer set visualization tool IDPDraw

Authors

AspCcgTk has been developed by

• Yuliya Lierler
• Peter Schüller