Prolog Programming Language

Prolog Programming Language Diagram

Overview

Prolog (from PROgramming in LOGic) is a general-purpose logic programming language associated with artificial intelligence and computational linguistics. It has a strong relationship with conceptual graphs.

History

1972

First Implementation

Prolog was developed in 1972 by Alain Colmerauer and Philippe Roussel at the University of Aix-Marseille. The first implementation appeared in 1973.

  • 1981 - Introduction of the Predicate Compiler as a second implementation of Prolog
  • 1986 - The ISO standard for Prolog established
  • 1990s - Prolog used in expert systems and natural language processing applications

Key Features

  • Declarative Programming Model: Programs specify what solutions must satisfy
  • Pattern Matching: Using unification to match facts and rules
  • Backtracking: Built-in support for exploring multiple solutions
  • Relational Data Model: Programs represent knowledge as relationships

Syntax Example

% Define family relations
parent(john, lisa).
parent(john, mike).

father(X, Y) :- parent(X, Y), male(X).

% Query: Who is John's child?
% ?- parent(john, Child).
% Child = lisa;
% Child = mike.

This example defines family relationships and demonstrates how to query these relationships in Prolog.

Applications

Artificial Intelligence

  • Expert systems and knowledge representation
  • Automated reasoning and theorem proving
  • Intelligent agents development

Natural Language Processing

  • Syntax and semantics analysis
  • Question answering systems
  • Language parsing

See Also