Prolog

• Artificial Intelligence
• Secondary Education
• University

Prolog Introduction

Prolog is a computer programming language.

It has been chosen by many programmers for applications of symbolic computation, including-

1. Relation databases
2. Mathematical logic
3. Abstract problem solving
4. Understanding natural language

Prolog Introduction...Continued

  5. Design Automation

  6. Symbolic Equation Solving

  7. Biochemical Structure analysis

  8. Many areas of ARTIFICIAL INTELLIGENCE

      ...... and many more 

Prolog Syntax

Terms: It is the central data structure in Prolog.

Types of Terms:

• Constants   -  Atoms,  Numbers

• Variables
  
• Compound terms or Structures
  
• Ground Term -    A term that doesn’t contain any variables is called a ground term.

Compound Term / Structure

It is a single object consisting of a collection of other objects, called Components.

Functor: It names the general kind of structure and corresponds to a data-type in an ordinary programming language.

Components: are enclosed in round brackets and separated by commas.

Components can be any prolog term i.e., atoms, numbers, variables, or other structures.

Example:

• owns(john, book(wuthering_heights, bronte)).
  
• owns(john, book(wuthering_heights, author(emily,bronte))). 
• Is_bigger(horse,X), 
• f(g(X, _), 7), 
• ‘My Functor’(dog)
  

Test the Unification

pilots(A,london) = pilots(london, paris)

points(X,Y,Z)=points(X1,Y1,Z1)

p(X,2,2) = p(1,Y,X).

p( _, 2, 2) = p( 1, Y, _).

Comments in prolog

Single Line Comments: 

•      Starts with percent (%) sign.
•      example-   
•            aunt( X, Z ) :- 
•                    sister( X, Y ),     % A comment on this suboal.
•                     parent( Y, Z).

Example - 

Comments in prolog

Multi-line comments:

•  These are enclosed between the two signs /* and */.
•  Example - 
•       /* This is a comment.  */

Q. Given the following predicates, ask the name of the person, whose position you want to ask, and return the position of the person using a declarative statement.

position("Komal",'Teacher').

position('Joy','director').

position("Raj",manager).

position('Hasan','supervisor').

Example using write / read

position("Kowalczyk",'Teacher').

position('Joy','director').

position("Raj",manager).

position('Hasan','supervisor').

find_position:-

        write('Whose position do you wish to know?'),nl,

        read(Input), position(Input, Output),

        write('The position of '), write(Input),

        write(' is '), write(Output), write(' . ').

Represent the following statements in the form of clauses 

1. John is a thief.
2. John likes anything that likes wine.

3. Mary likes wine.
4. Mary likes Chocolates.

5. A person may steal something if the person is a thief and the person likes the thing.

Given the above mentioned rules and facts, infer the information 'what John can steal...'

Q2.   Given the reigns of Mughal Emperors as facts, create a rule that can answer who was on the Indian throne during a particular year.

reigns( babur, 1526, 1530).

reigns( humayun, 1530, 1540).

reigns( humayun, 1555, 1556).

reigns( Akbar, 1556, 1605).

reigns( jahangir, 1605, 1627).

reigns( shahjahan, 1628, 1658).

Q3. Given the population and area of a country, find its population density.

pop( india, 548 ).

pop( china, 800 ).

pop( brazil, 108 ).

pop( usa, 203 ).

area( usa, 3 ). 

area( india, 1 ).

area( china, 4 ).

area( brazil, 3 ).

Question-4

Write a predicate that takes two numbers as input and gives the result of the following arithmetic operations:

• Addition                                                      minimum(x,y)
• Subtraction                                               maximum(x,y)
• Integer Division                                       squareRoot(X)
• Multiplication
• x^y

Q. Given the following predicates, ask the name of the person, whose position you want to ask, and return the position of the person using a declarative statement.
position("Komal",'Teacher').
position('Joy','director').
position("Raj",manager).
position('Hasan','supervisor').

Success Criteria- Now ,I CAN
create facts, rules in prolog clearly, and understand the applications of prolog by implementing it.

1. Strongly Agree
2. Agree
3. Not Sure
4. Need Help

THANK YOU!