Examples for the prolog
Example1: Write a prolog program to check if the given number is positive or negative.
sol//
Domains I= integer
Predicates pos_neg(i)
Clauses pos_neg(X):-X>=0, write(“positive number”),nl.
pos_neg(_ ):-write(“negative number”),nl.
Goal pos_neg(4).
Output:
positive number
Example2: write a prolog program to check if a given number is odd or even.
sol//
Predicates
odd_even(integer)
Clauses
odd_even(X):-X mod 2= 0, write (“even number”), nl.
odd_even(X):- X mod 2 <> 0, write (“odd number”), nl.
Goal odd_even(5).
Output:
odd number
Example3: Write a prolog program to combine both rules in example1 and example2.
sol//
Domains
I= integer
Predicates
pos_neg(i)
odd_even(i)
oe_pn(i)
Clauses
oe_pn(X):-pos_neg(X),odd_even(X).
odd_even(X):-X mod 2= 0, write(“ even number”),nl.
odd_even(X):- write(“odd number”),nl.
pos_neg(X):-X>=0, write(“positive number”),nl.
pos_neg(_ ):-write(“negative number”),nl.
Goal oe_pn(3).
Output:
odd number
positive number
Example4: write a prolog program that take two integers as input and print the greater one.
sol//
Domains
i = integer
Predicates
greater ( i,i)
Clauses
greater(X,Y):- X>Y,write(“the greater is”,X).
Greater(X,Y):- Y>X, write (“ the greater is “,Y).
Goal Greater(4,3).
Output:
The greater is 4
Example5: program to print number from n to 1.
sol//
Predicates
a (integer)
Clauses
a(1) :- write (1), nl ,!.
a(M):- write (M) , nl, M1 = M -1, a( M1).
Goal a(4).
Output:
4
3
2
1
Yes
Example 6: program to find factorial. 5! = 5*4*3*2*1
sol//
Predicates
fact ( integer, integer, integer)
Clauses
fact(1, F, F):-!.
fact(N,F,R):- F1=F*N , N1=N-1, fact(N1,F1,R).
Goal fact (5,1,F).
Output:
F = 120.
Example 7: program to find power . 3 4 = 3*3*3*3.
sol//
Domains
I= integer
Predicates
power ( I,I,I, I ).
Clauses
power (_,0,P,P):-!.
power ( X,Y,P,R):- P1= P*X, Y1 =Y-1, power(X,Y1,P1,R).
Goal power(3,2,1,R).
Output
R= 9
Example8: program without using cut.
sol//
Domains
I= integer
Predicates
no( I )
Clauses
no (5):-!.
no (7).
no (10).
Goal no (X).
Output:
X=5
Example9: program without using cut.
sol//
Domains
I =integer
S = symbol
Predicates
a (I )
b (s )
c ( I, s )
Clauses
a(10).
a(20)
b(a)
b(c)
c (X,Y):- a(X), b(Y).
Goal c(X,Y).
Output:
X= 10 Y=a
X=10 Y=c
X=20 Y=a
X=20 Y=c
Example 10: using cut at the end of the rule.
sol//
Domains
I =integer
S = symbol
Predicates
a(I )
b (s )
c (I, s )
Clauses
a(10).
a(20)
b(a)
b(c)
c (X, Y):- a (X), b (Y),!.
Goal c(X,Y).
Output:
X= 10 Y=a
Example 11: using cut at the middle of the rule.
sol//
Domains
I =integer
S = symbol
Predicates
a(I )
b (s )
c ( I, s )
Clauses
a(10).
a(20)
b(a)
b(c)
c (X,Y):- a(X),!, b (Y).
Goal c(X,Y).
Output:
X=10 Y=a
Y=c
Example 12: Calculate counter from 1-10.
sol//
domains
i=integer
predicates
counter(i)
counter(10):-!.
counter(X):-write(X), X1=X+1, counter(X1).
Goal: counter(1)
Output: 1 2 3 4 5 6 7 8 9
Example 13: Calculate summation of 10 numbers
sol//
predicates
sum(integer,integer,integer)
clauses
sum(10,S,S):-!.
sum(X,Y,S):-Y1=Y+X,X1=X+1,sum(X1,Y1,S),!.
Goal: sum(1,0,M)
Output: ?
Example 14: Calculate summation of 10 given integer numbers.
sol//
domains
int=integer
predicates
sum_int(int,int,int)
clauses sum_int(10,S,S):-!.
sum_int(X,Y,S):-readint(Z),Z>0, X1=X+1,Y1=Y+Z,sum_int(X1,Y1,S),!.
sum_int(X,Y,S):-X1=X+1,sum_int(X1,Y,S),!.
Goal: sum_int(1,0,M)
Output: ?
Example 15: Print the contents of a list.
sol//
domains
ilist=integer*
predicates
print(ilist)
clauses
print([]).
print([X|T]):-write(X),print(T).
Goal: print([3,4,5])
Output: 3 4 5 yes
Example 16: Program to find sum of integer list.
sol//
Domains
I= integer
L=i*
Predicates
Sum ( L ,I, I)
Clauses Sum ( [ ],S,S):-!.
Sum( [H| T],S1,S):- S2 = S1+H , Sum (T,S2,S).
Goal Sum ( [ 1,4,6,9],0 ,S).
Output S = 20 yes
Example 17: Prolog program to spilt list into positive list and negative list.
sol//
Domains
L= integer*
Predicates
Spilt ( L,L,L)
Clauses Spilt ( [ ],[ ],[ ]):-!.
Spilt ( [ H| T],[H|T1],L2):- H>= 0,!,spilt (T, T1,L2).
Spilt ([H|T],L1,[H|T2] ) :- spilt ( T,L1,T2).
Goal Spilt ([-1,4,-9,8,0],L1,L2).
Output
. L1 = [4,8,0]
L2 = [-1,-9]
Example 18:Find the maximum value of the list.
sol//
domains
ilist=integer*
predicates
list(ilist,integer)
clauses
list([H],H).
list([H1,H2|T],H):-H1>H2,list([H1|T],H).
list([_,H2|T],H):-list([H2|T],H).
Goal: list([3,9,4,5],M)
Output:
M=9 yes
[3,9,4,5]
[9,4,5]
[9,5]
[9]
Example 19:Append two lists.
sol//
domains
ilist=integer*
predicates
app(ilist,ilist,ilist)
clauses
app([],L,L).
app([X|L1],L2,[X|L3]) :-app(L1,L2,L3).
Goal: app([3,4,5],[6,7,8],L)
Output: L=[3,4,5,6,7,8] yes
Example 20:Write the contents of list inside at the given list
sol//
domains
ilist=integer*
lists=ilist*
predicates
list(lists)
clauses
list([]).
list([[]]).
list([[H|T]]):-write(H),list([T]).
list([H|T]):-list([H]),list(T).
Goal: list([[3,4,5],[6,7,8]])
Output: 3 4 5 6 7 8 yes
Example 21:Reveres the contents of the given list
sol//
domains
slist=symbol*
predicates
rev(slist,slist)
app(slist,slist,slist)
clauses
app([],X,X).
app([H|T1],X,[H|T]):-app(T1,X,T).
rev([X],[X]). rev([H|T],L):-rev(T,L1),app(L1,[H],L).
Goal: rev([a,b,c,d],R)
Output: R=[d,c,b,a]
Example 22:Delete a particular element from a list
sol//
domains
i= integer
l= i*
Predicates
Delall (i,l,l)
Clauses
Delall (_,[ ],[ ]):-!.
Delall (X,[X|T1],T1) :-!.
Delall (X,[ H|T1],[H|T2]):- Delall (X,T1,T2).
Goal Delall(2,[1,3,2,3,2,1],X).
Output=?
Example 23:Finding the first element in a list (front).
sol//
s_list =symbol*
predicates
front(symbol , s_list )
clauses
front(E,[ E | _ ]).
goal:front(X,[ a,b,c].
.Example 24:Finding the last element in a list (front).
sol//
domains
s_list =symbol*
predicates
last(symbol , s_list )
clauses
last(E,[ E ]).
last( E , [ _ | T ] ):- member(E,T).
goal:last(X,[a,b,c]).
.Example 25:adding an element to a list .
sol//
s_list =symbol*
predicates
add_first(symbol , s_list,s_list )
clauses
add_first(E,L,[ E| L ]).
output
goal:add_first(ban,[ahmed,noor],R)
R=[ban,ahmed,noor]
1solution
.Example 26:adding element to the end of a list.
sol//
s_list =symbol*
predicates
add_last(symbol , s_list,s_list )
clauses
add_last(E,[ ] ,[ E ]).
add_last( E , [ H| T1], [ H|T2]):-add_last(E , T1,T2).
output
goal:add_last(ban,[ahmed,noor],R)
R=[ahmed,noor,ban]
1solution
.Example 27:Delete the first occurrence element from a list
sol//
s_list =symbol*
predicates
delete_first(symbol , s_list,s_list )
clauses
delete_first(E, [E|L], L ) :-! .
delete_first(E, [H|T1],[H|T2]):-delete_first
(E,T1,T2).
output
goal:delete_first(ban,[ahmed,ban,noor,ban],R)
R=[ahmed,noor,ban]
1solution.
.Example 28:Deleting all occurrence of an element from a list
sol//
s_list =symbol*
predicates
delete_all(symbol , s_list,s_list )
clauses
delete_all( _ , [ ] , [ ] ):-! .
delete_all(E, [E|T1],T2):-! , delete_all(E,T1,T2).
delete_all(E,[H|T1],[H|T2]):-delete_first(E,T1,T2).
output
goal:delete_all(ban,[ahmed,ban,noor,ban],R)
R=[ahmed,noor]
1 solution
example 29/
sol/
