Lists are an important data structure in Prolog. A list consists of a head, which is the first element, and a tail, which is the remaining list. Functions in Prolog are called predicates and perform operations like addition, subtraction, multiplication and division by using parameters and returning a result. Lists and functions can be manipulated and applied through examples like adding elements to a list or performing mathematical operations on numbers.

1. Recursion Basic ,List
Manipulation and Function
Prof. Neeraj Bhargava
Kapil Chauhan
Department of Computer Science
School of Engineering & Systems Sciences
MDS University, Ajmer

2. contents
 Recursion Introduction
 List
 List manipulation
 List manipulation Example
 Functions
 Functions example

3. Recursion Introduction
 The recursion in any language is a function that can call
itself until the goal has been succeed.
 The best way in Prolog to calculate a factorial is to do it
recursivelly. Here is an example of how it can be done :
 factoriel(0,1).
 factoriel(X,Y)
 :- X1 is X - 1,
 factoriel(X1,Z),
 Y is Z*X,!.
after the first solution. Now if you enter :
?- factoriel(5,X).
X = 120
Yes

4. list
 we have only considered simple items as arguments
to our programs.
 [first,second,third] = [A|B]
 where A = first and B=[second,third]
 List is one of the most important data structure in
Prolog.
 Here are some example simple lists
[a,b,c,d,e,f,g]
[apple,pear,bananas,breadfruit]
 Consider the following fact.
?- p([a,b,c], X, Y).
 X=a
 Y=[b,c]
 yes

5. list manipulation
 The first element of a list is called its head and the
remaining list is called the tail.
 An empty list doesn’t have a head.
 A list just containing a single element has a head
 [Nepal | [India, Bhutan, Sri Lanka, Maldives,
Pakistan, Bangladesh]]
 Nepal is head and remaining countries constitute tail
and this is represented as

6. output
?- sky([1,2,3,4,5,6],X).
X = [1, 3, 5, 2, 6, 4] ;
false.
?- sky([1,2,3,4,5,6,7,8,9],X).
X = [1, 3, 5, 7, 9, 2, 6, 4, 8] ;
false.

7. functions
 Defining four functions (it’s called predicates in prolog),
addition, subtraction, multiplication, and division.
 Each of them takes three parameters, the result is saved to
the third parameter.
 Functions are normal Prolog predicates.
 Some predicates are already predefined when you start your
Prolog system. These are called built-in predicates or
simply built-ins.

8. Functions example
addition(A, B, C):- C is A + B.
subtraction(A, B, C):- C is A - B.
multiplication(A, B, C):- C is A * B.
division(A, B, C):- C is A / B.
?- addition(2,3,X).
X = 5.
?- subtraction(4,2,X).
X = 2.
?- multiplication(3,4,K).
K = 12.
?- division(9, 3, D).
D = 3.

9. Assignment
 Explain List and function manipulation in prolog with
example