Introduction

Abduction is a powerful logical inference for seeking hypothetical explanation(s) for an observation given some background knowledge. The combination of abduction and logic programming, called abductive logic programming (ALP) [1], allows many AI problems such as diagnosis, planning/scheduling, and cognitive perception to be modelling in logic and solved.

abduction is a module for SICStus Prolog (version 4.1.1, tested on both Windows and Linux), and is a re-implementation of the well-known abductive logic programming system called ASystem [3,2], with the following differences and enhancements:

• it allows the usage of arithmetic constraints over both finite domains and reals;
• it allows abducible argument types to be specified;
• all the code is in a single source file (as a module), and hence can be used as a standalone system or be easily integrated into the user's Prolog programs.

This document is written for helping the readers to get started using abduction. It is expected that the readers are familiar with Prolog and have knowledge of abductive logic programming.