This document provides an introduction to Prolog, including: - Current popular Prolog implementations like SWI-Prolog. - SWI-Prolog can be downloaded for free and runs on Windows and Linux. - Prolog is a logical and declarative programming language, where programs logic to solve problems. - Prolog has applications in areas like intelligent data retrieval, expert systems, machine learning, and robot planning by using facts, rules, queries, variables, and unification.

1. Introduction
To
PROLOG
PREPARED BY-
SHOWKOT USMAN
ID: 15-02-01-008
DEPT. OF CSE
GUB
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2. 2
 Introduction
 CURRENT IMPLEMENTATIONS
 SWI_PROLOG
 Fundamentals of PROLOG
 Applications
 References
Objective

3.  Prolog is the most popular language of the logic
programing languages.
 It is goal based language, it has automatic
backtracking and uses recursion.
 Prolog stands for programmation en logique", or
programming in logic.“
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Introduction

4. CURRENT
IMPLEMENTATIONS
There are several popular Prolog interpreters
available. They include:
1.GNU Prolog (http://pauillac.inria.fr/vdiaz/gnuprolog/)
2. Visual Prolog (http://www.visualprolog.com/vip6/Download/Default.htm)
3. Bprolog
(http://www.cad.mse.kyutech.ac.jp/people/zhou/bpr
olog.html)
4. SWI_PROLOG
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5.  SWI-Prolog offers a comprehensive FREE
Software Prolog environment.
 Link for downloading:
http://www.swi-prolog.org/download/stable
 A Self-installing executable for Windows: swipl-win.exe
 Works on Windows XP
 LINUX versions are also available.
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SWI_PROLOG

6. o Prolog is a logical and a declarative
programming language.
o The name itself, Prolog, is short for
Programming in Logics.
o Prolog is the major example of a fourth
generation
programming language supporting the
declarative programming paradigm.
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What is Prolog ?

7. Applications of Prolog
Some applications of Prolog are:
 Intelligent data base retrieval
 Natural language understanding
 Expert systems
 Specification language
 Machine learning
 Robot planning
 Problem solving
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8. 1. Facts
2. Rules
3. Query
4. Variables
5. Unification
6. Resolution
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Fundamentals

9.  The Prolog system uses the facts to work out how
to accomplish the solution by searching through
the space of possible solutions.
 It is defined by an identifier followed by an n-
tuple of constants.
 A relation identifier is referred to as a predicate
 When a tuple of values is in a relation we say the
tuple satisfies the predicate.
 Names of relationship and objects must begin
with a lowercase letter.
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Facts

10. 1. Specifies under what conditions a tuple of
values satisfies a predicate.
2. The basic building block of a rule is called an
atom
3. Atom :- Atom1, ..., Atomn
If each of Atom1,...,Atomn is true, then Atom is
also true.
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Rules

11. There are two types of queries:
1.Ground Query
 edge(a,b)
 This query is called a ground query because it consists only of
value identifiers as parameters to the predicate.
 a ground query is posed we expect a yes/no answer.
2. Non Ground Query
 They have variables as parameters
 tedge(a,X)
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Query

12.  Always begin with a capital letter
 ?- likes (john,X).
 ?- likes (john, Something).
 But not
 ?- likes (john,something)
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Variables

13. Example
 Facts: ()
◦ likes(john,mary).
◦ likes(john,X). % Variables begin with capital
 Queries
◦ ?- likes(X,Y).
◦ X=john, Y=Mary. % hit “;” for more
◦ ?- likes(X,X).
◦ X=john.
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14.  Prolog associates variables and values using a
process
known as unification
 Variables that receive a value are said to be
instantiated
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Unification

15. Arithmetic in prolog
 Prolog provides a number of basic arithmetic tools.
 Arithmetic examples Prolog Notation
 6 + 2 = 8 8 is 6+2.
 6 *2 = 12 12 is 6*2.
 Answers to arithmetic questions by using ariables.
 For example:
?- X is 6+2.
X=8
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16. References
 Artificial Intellegence & Expert System
DAN .W PATERSON
 www.swi-prolog.org/
 http://www.learnprolognow.org
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17. Thank You
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