AbdelAli Ed-Dbali

Software Formal Specification by Logic Programming: The Example of Standard Prolog

The aim of this presentation is to show how logic programming can be used to make formal specifications. This approach is illustrated by the project of standard Prolog, as discussed in the ISO working group, which has been completely described by a formal specification.

Learning Approximate Consistencies

In this paper, we present an abstract framework for learning a finite domain constraint solver modeled by a set of operators enforcing a consistency. The behavior of the consistency to be learned is taken as the set of examples on which the learning process is applied. The best possible expression of this operator in a given language is then searched. We present sufficient conditions for the learned solver to be correct and complete with respect to the original constraint. We instantiate this framework to the learning of bound-consistency in the indexical language of Gnu-Prolog.

Prolog Environment: Sources and Sinks

This chapter describes the I/O system of Standard Prolog and how terms are input and output.

Writing Portable Programs

The purpose of this chapter is to introduce some methodology to help write portable programs easily.

The Built-in Predicates

The built-in predicates are system procedures. They cannot be modified. All are static and private.

Prolog Execution Model

In this chapter, the execution model of Standard Prolog is described. It formalises its main characteristics: nondeterminism (multiplicity of the solutions), backtracking and control. Knowledge of this is needed in order to understand the meaning of many built-in predicates and the behaviour of a program.

Prolog Flags and Directives

In Standard Prolog Flags are reserved atoms with an associated predefined value, which define some parameters of a processor. Some of them are fixed with a given processor; their value is implementation defined and cannot be updated. Some others may be modified by the user and are said changeable.

Prolog Data Structures

Basic abstract data structures, sufficient to understand the execution model and the meaning of the built-in predicates, are introduced. The full syntax of these data structures is given in Chapter 9.