my prolog presentation

8/2/2019 My Prolog Presentation

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Programming LanguageInstructor:

Dr. Einollah Khanjari

By:Omid ShirkhorshidiThe slides included information was taken from the Site Wikipedia And Books:1) Learn Prolog Now!, Patrick Blackburn, Johan Bos, Kristina Striegnitz, 2006

2) PROLOG Programming for Artificial Intelligence, William F. Clocksin, Christopher S., 20003) Programming in Prolog: Using the ISO Standard. Springer, 5th ed., 2003

Spring 2011


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1. HistoryOf Prolog Language

2. A BriefIdentification3. Basic Elements and How to Program?4. Syntax and semantics & Some Examples5. Usages6. WhyProlog?

7. Criticisms About this language8. References


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History OfProlog Language

Alain Colmerauer Philippe Roussel

Creator :Alain Colmerauer with Philippe Roussel

Date Of Creation :Around 1972

Based On Past Works Of :Robert Kowalski

Prolog Is An Abbreviation Of:programmation en logique

(French for programming in logic)

Robert Kowalski


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Brief IdentificationProlog is a general purpose logic programming language associated with artificial intelligence

and computational linguistics.

There is some Useful Information :

1. Paradigms : Logic Programming ( It should be mentioned here that thereare many extensions ofProlog with other Paradigmsfeatures)

2. Some FeaturesOf Prolog : Declarative, Reflective , Rule-based &High-level interactive language.


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Brief Identification3. Major implementations (Extensions) :

HiLogand Prologextend Prolog with higher-order programming features.

Logtalkand Oblogare some prolog extension with Object Orientation features.

SWI-prolog,Visual-prolog and B-Prologare some Prolog systems thatprovide a graphics library.

Some Prolog implementations, notablySWI-Prolog, support server-side webprogramming with support for web protocols, HTML andXML.

4. Usual File Extensions : .PL & .PRO

5. Web-site : ????????????????????????????????
http://en.wikipedia.org/wiki/HTMLhttp://en.wikipedia.org/wiki/XMLhttp://en.wikipedia.org/wiki/XMLhttp://en.wikipedia.org/wiki/HTML


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What is a Declarative Lang.?Programming languages are of two kinds:

Procedural: (BASIC, ForTran, C++, Pascal, Java);Declarative: (LISP, Prolog, ML).

In procedural programming, we tell the computer how to solve a problem.

In declarative programming, we tell the computer whatproblem we want solved.

(However, in Prolog, we are often forced to give clues as to the solution method).


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Our program is a database offacts and rules.

Some are always true (facts):father( john, jim).

Some are dependent on others being true (rules):parent( Person1, Person2 ) :-

father( Person1, Person2 ).

To run a program, we ask questions about thedatabase. (Queries)

Basic Elements of Prolog:


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Example Database In English:John is the father of Jim.Jane is the mother of Jim.Jack is the father of John.

Person 1 is a parent of Person 2 if

Person 1 is the father of Person 2 orPerson 1 is the mother of Person 2.

Person 1 is a grandparent of Person 2 ifsome Person 3 is a parent of Person 2 andPerson 1 is a parent of Person 3.

Example questions In English:Who is Jim's father?Is Jane the mother of Fred?Is Jane the mother of Jim?Does Jack have a grandchild?

Example Database In Prolog:father( john, jim ).mother( jane, jim ).father( jack, john ).

parent( Person1, Person2 ) :-father( Person1, Person2 ).

parent( Person1, Person2 ) :-mother( Person1, Person2 ).

grandparent( Person1, Person2 ) :-parent( Person3, Person2 ),parent( Person1, Person3 ).

Example questions In Prolog:

?- father( Who, jim ).?- mother( jane, fred ).?- mother( jane, jim ).?- grandparent( jack, _ ).

Basic Elements of Prolog:


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.pl files contain lists of clauses.

Clauses can be either facts or rules.

The Prolog comment characters:

Single line comments: (%)

% This is a commentThis is not a comment, but an error

Multiple line comments: ( /* */ )/* This is a multi-line commentwhich must be closed with a */


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Prolog's single data type is the term. Terms are either atoms, numbers, variablesor compound terms.

1)An atom is a general-purpose name with no inherent meaning. Examples ofatoms include x, blue, 'Taco', and 'some atom'.

2)Numbers can be floats or integers.
http://en.wikipedia.org/wiki/Floating_pointhttp://en.wikipedia.org/wiki/Integerhttp://en.wikipedia.org/wiki/Integerhttp://en.wikipedia.org/wiki/Floating_point


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3)Variables are denoted by a string consisting of letters, numbers and underscorecharacters, and beginning with an upper-case letter or underscore. Variables

closely resemble variables in logic in that they are placeholders for arbitrary terms.

4)Acompound term is composed of an atom called a "functor" and a number of"arguments", which are again terms.

Examples of compound terms aretruck_year('Mazda', 1986)

and'Person_Friends'(zelda,[tom,jim]).


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Arule is of the form:Head :- Body.

and is read as "Head is true if Body is true".

An example of a fact is:cat(tom).

which is equivalent to the rule:cat(tom) :- true.

An example of a rule is:animal(X):- cat(X).

Given the beside fact, one can ask:is tom a cat?

?- cat(tom).Yes

what things are cats??- cat(X).X = tom

If we add that rule and ask

what things are animals?

?- animal(X).

X = tom


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greetings:-

write(What is your name?),

nl,

read(X),

write(Hello ),

write(X).

| ?- greetings.

What is your name?

|: tim.

Hello tim

X = tim ?

yesProlog Code Terminal

mother_child(trude, sally).father_child(tom, sally).father_child(tom, erica).father_child(mike, tom).sibling(X, Y) :- parent_child(Z, X), parent_child(Z, Y).

parent_child(X, Y) :- father_child(X, Y).parent_child(X, Y) :- mother_child(X, Y).

This results in the following query being evaluated as true:?- sibling(sally, erica).Yes

Prolog Code

Terminal


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Recursive Definitions

For all X and YX is in Ys food chain if

Y eats X

orY eats some Z and X is in Zs food chain:

food_chain(X,Y) :- eats(Y,X).

food_chain(X,Y) :- eats(Y,Z),food_chain(X,Z).Afterwards we can ask:?-food_chain(X,rat).X=salmon;X=wormOr:?-food_chain(worm,X).X=rat;

X=bear


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Hello world !

As an example of a query:?- write('Hello world!'), nl.

Hello world!

true.

?-


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Artificial intelligence or any Intelligent systems

Complicated knowledge databases Natural language processing Logic data analysis

intelligent data base retrieval natural language understanding expert systems specification language machine learning robot planning automated reasoning problem solving


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Prolog is interactive. It comes with a top-level interpreter: a command interfacethat you can type code at and get itexecuted immediately.

Prolog is fast.

Some extensions like SWI-Prolog are free,open-source, and very well maintained.

Unlike many other programminglanguages, Prolog is declarative


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Complicated syntax

Difficult to understand programs at first sight

Programming in the large is considered to be complicated because notall Prolog compilers support modules, and there are compatibilityproblems between the module systems of the major Prolog compilers.

Portability of Prolog code across implementations has also been aproblem


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The slides included information was takenfrom the Site Wikipedia And Books:

1) Learn Prolog Now!, Patrick Blackburn,Johan Bos, Kristina Striegnitz, 2006

2) PROLOG Programming for ArtificialIntelligence, William F. Clocksin, Christopher

S., 2000

3) Programming in Prolog: Using the ISOStandard. Springer, 5th ed., 2003


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my prolog presentation

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