DEFT

DEFT for Defeasible Datalog+/- is an open source software for Defeasible Reasonning based on Graal. It is still under active developpment and offers a working API for defeasible reasonning in Datalog+/-.

For more details and examples See DEFT homepage.

Installation

Two ways to do it:

1. Easy way: Go to target and download `DEFT-{version}-jar-with-dependencies.jar'. It contains all the dependencies including Graal.

2. Or, Flexible way:

• install graal as a maven dependency: graal installation.
• Clone the DEFT repository

  https://github.com/hamhec/DEFT.git

• go to the DEFT folder and package it

  mvn clean install

• add DEFT as a maven dependency to your project.
• profit :).

Usage

1. Express your knowledge base using the DLGP format. e.g. kowalski.dlgp

   
   % kowalski.dlgp
   %----------------- Rules --------------------
   bird(X) :- penguin(X).
   nofly(X) :- penguin(X).
   [DEFT] fly(X) :- bird(X).

%----------- Negative Constraints ----------- ! :- nofly(X), fly(X).

%----------------- Facts -------------------- penguin(kowalski).

2. in your code, create a KB object using the dlgp file, and saturate the knowledge base

KB kb = new KB("path/to/kowalski.dlgp"); kb.saturate();

3. Transform your atomic query to an atom

Atom atom = kb.getAtomsSatisfiyingAtomicQuery("?(X) :- nofly(kowalski).").iterator().next();

4. Set the preference function to use

kb.setPreferenceFunction(new GeneralizedSpecificityPreference());

5. Get its entailment status

int entailment = kb.EntailmentStatus(a); / the KB class contains constants explaining the entailement status: NOT_ENTAILED, STRICTLY_ENTAILED, DEFEASIBLY_ENTAILED /

## Next Versions TODO List

- Add detailed documentation.
- Add preference on rules.
- Add support for default negation.
- Add a graphical tool for dialectical tree visualisation.

## Contributing

1. Fork it!
2. Create your feature branch: `git checkout -b my-new-feature`
3. Commit your changes: `git commit -am 'Add some feature'`
4. Push to the branch: `git push origin my-new-feature`
5. Submit a pull request :D

## License

DEFT is an open-sourced software licensed under the [MIT license](http://opensource.org/licenses/MIT)