ELDR (Existential Logic for Defeasible Reasoning)

This a Defeasible Logic reasonner for Existential rules, it allows for Ambiguity Blocking or Propagating, with or without Team Defeat.

Getting Started

You can either import this module using Maven Central (recommended). Add the following to your pom.xml:

<dependency>
      <groupId>fr.lirmm.graphik</groupId>
      <artifactId>graal-elder</artifactId>
      <version>1.0.1</version>
</dependency>

Or using Github then adding it to your project:

> git clone https://github.com/hamhec/graal-elder.git

Example

See Graal-Defeasible-Core for more information on the format.

kb.add("penguin(kowalski), bird(tweety), brokenWings(tweety).");
kb.add("beautiful(X) <- penguin(X).");
kb.add("sad(X) <- brokenWings(X).");

kb.add("notFly(X), bird(X) <- penguin(X).");
kb.add("[rfly] fly(X) <= bird(X).");
kb.add("[rbroken] notFly(X) <~ brokenWings(X) .");

kb.add("! :- fly(X), notFly(X).");

kb.add("rbroken >> rfly .");

// Statement Graph takes a knowledge base and a labeling function, BDLwithoutTD means Blocking with no Team Defeat
StatementGraph sg = new StatementGraph(kb, new BDLwithoutTD(kb));

sg.build();

String answer = sg.groundQuery("fly(kowalski)"); // does kowalski fly?
System.out.println(answer); // OUT

answer = sg.groundQuery("notFly(kowalski)"); // does kowalski not fly?
System.out.println(answer); // DEFEASIBLE_IN

answer = sg.groundQuery("fly(tweety)"); // does kowalski fly?
System.out.println(answer); // OUT

answer = sg.groundQuery("notFly(tweety)"); // does kowalski not fly?
System.out.println(answer); // UNSUPPORTED

answer = sg.groundQuery("happy(kowalski)"); // does kowalski fly?
System.out.println(answer); // UNSUPPORTED

Publications and Theory

Defeasible Reasoning intuitions, semantics and Proofs for equivalence between SG labelings and Defeasible Logics can be found in THESIS (Chapter 2, 4, and 7).

Known Issues

ELDR does not currently support cycles (positive and negative loops). We are currently working on it.

Authors

• Abdelraouf Hecham - Developement and Maintenance - Hamhec

License

This project is licensed under CeCILL 2.1 - see the LICENSE file for details