aleph

##Index

1. Introduction
2. Usage
3. New induction commands
4. Manual
5. Examples

Introduction

Porting of Aleph for SWI-Prolog.

Aleph is an Inductive Logic Programming system developed by Ashwin Srinivasan:

http://www.cs.ox.ac.uk/activities/machlearn/Aleph/

This pack contains a porting of Aleph v.5 to SWI-Prolog. The porting was done by Fabrizio Riguzzi.

Two files are included: aleph_orig.pl is a direct porting of Aleph for Yap, while aleph.pl is modoule-file that can run also under SWISH. aleph.pl was developed by Paolo Niccolò Giubelli.

Usage

aleph_orig.pl can be used as the original Aleph.

aleph.pl differs because it uses a single input file instead of three files for background, positive and negative examples.

The input file for aleph.pl must be structured as follows:

1. Module loading

:- use_module(library(aleph)).

2. Aleph initialization

:- aleph.

3. Directives Nothing has changed here, you can use modeh/2, modeb/2, determination/2 as documented in the manual

% e.g.: 
:- modeh(*,grandparent(+person,-person)).
:- modeh(*,parent(+person,-person)).

:- modeb(*,mother(+person,-person)).
:- modeb(*,father(+person,-person)).
:- modeb(*,parent(+person,-person)).

% ...

4. Background Knowledge Section Nothing has changed here except you need to enclose this section with begin_bg/0 and end_bg/0 directives. Between them you can put your background clauses.

% Background knoweledge is delimited by begin_bg/0 and end_bg/0
% predicates. Look at the 
% E.g.:
:-begin_bg.
person(bob).
person(dad(bob)).
%...
:-end_bg.

5. Positive Examples Section

% The positive examples section is delimited by begin_in_pos/0 and end_in_pos/0
% directives.
% E.g.:
:-begin_in_pos.
grandparent(dad(dad(bob)),bob).
grandparent(dad(mum(bob)),bob).
%...
:-end_in_pos.

6. Negative Examples Section

% The negative examples section is delimited by begin_in_neg/0 and end_in_neg/0
% directives. Negative examples must be listed as facts.
% E.g.:
:-begin_in_neg.
grandparent(bob,bob). % bob is not a grandparent of bob
%...
:-end_in_neg.

7. End Section The file must contain the following directive at the end:

:-aleph_read_all.

You can start the induction process by calling the induce/1 predicate, which returns the theory as a list of clauses. induce/1 replaces the old induce/0 predicate.

New induction commands

The following predicates were created. Their arity has been increased by one compared to the original version. Program is the (new) output argument which returns the theory as a list of predicates.

• induce(-Program)
• induce_tree(-Program)
• induce_cover(-Program)
• induce_modes(-Modes)
• induce_incremental(-Program)
• induce_max(-Program)
• induce_features(-Features)
• induce_constraints(-Constraints)
• induce_theory(-Program)
• induce_clauses(-Program)

Manual

The manual can be found at http://www.cs.ox.ac.uk/activities/machlearn/Aleph/.

Examples

The examples have been downloaded from http://www.comlab.ox.ac.uk/oucl/research/areas/machlearn/Aleph/misc/examples.zip and ported to SWI-Prolog.