Download PROLOG HW1model answer

Princess Noura Bint Abdulrahman University
College of Computer Science and Information Systems
Computer Science Department
Submission is online
homework sent to the
CS461: Artificial Intelligence
Lab Homework #1
due date in Tuse,1April
Homework #1
by a link not by email. Any
email will be ignored.
Q1: Consider the following Prolog program:
father(ahmad,sami).
father(ahmad,khalid).
father(sami,dana).
father(sami,mohammed).
father(khalid,reem).
1. Define a Rule
which holds iff
brother(X,Y)
and
X
Y
are brothers.
brother(X,Y):-father(Z,X),father(Z,Y),not(X=Y).
2. Define a Rule
cousin(X,Y)
which holds iff
X
and
Y
are cousins.
cousin(X,Y) :- father(Z,X), father(W,Y), brother(Z,W).
3. Define a Rule
grandson(X,Y)
which holds iff
X
is a grandson of Y.
grandson(X,Y) :- father(Z,X), father(Y,Z).
4. Define a Rule
descendent(X,Y)
which holds iff
X
is a descendent of Y.
descendent(X,Y) :- father(Y,X).
descendent(X,Y) :- father(Z,X), descendent(Z,Y).
1) What Prolog answers to these questions (“True”, “False”, or variables bindings – write all possible
bindings ).
a.
?- brother(X,Y).
X = sami,
Y = khalid ;
X = khalid,
Y = sami ;
X = dana,
Y = mohammed ;
X = mohammed,
Y = dana ;
false.
b.
?- cousin(dana,Y).
Y = reem.
c.
?- grandson(X,reem).
false.
d.
?- descendent(ahmad,reem).
false.
Princess Noura Bint Abdulrahman University
College of Computer Science and Information Systems
Computer Science Department
CS461: Artificial Intelligence
Lab Homework #1
due date in Tuse,1April
Q2: Which of the following are syntactically correct Prolog objects? What kind of objects are they? (atom ,
number , variable , structure)
a. Diana variable
b. Diana atom
c. 'Diana' atom
d. _diana variable
e. 'diana goes south' atom
f. goes (diana,south) structure
g. 45 number
h. 5(X,Y) incorrect
i. +(north, west) structure
j. three(black(cats)). Structure
Q3: Will the following matching operation succeed or fail? If they succeed, what are the resulting
instantiation of variables?
a) point( A, B) = point( 1, 2)
b) =(ann,'ann')
c) point( A, B) = point( X, Y, Z)
d) plus( 2, 2) = 4.
e) +( 2, D) = +( E, 2).
f) triangle( point(-1,0), P2, P3) = triangle( P1, point(1,0), point(0,Y) )
g) parent (adam, liz) = X.
h) ?- point(A,B) = point(1,2).
A=1
B=2.
i) =(ann,'ann').
True.
j) ?- point(A,B) = point(X,Y,Z).
False.
k) ?- plus(2,2) = 4.
False.
l) ?- +(2,D) = +(E,2).
D=2
E=2.
m) ?- triangle(point(-1,0),P2,P3) = triangle(P1,point(1,0),point(0,Y)).
P2 = point(1, 0)
P3 = point(0, Y)
P1 = point(-1, 0).
n) ?-parent (adam, liz) = X.
X = parent(adam, liz).
Princess Noura Bint Abdulrahman University
College of Computer Science and Information Systems
Computer Science Department
CS461: Artificial Intelligence
Lab Homework #1
due date in Tuse,1April
Q4: Consider the following program:
f( 1, one).
f( s(1), two).
f( s(s(1)), three).
f(s(s( s(s(s(X))))), N) :-f( X, N).
How will Prolog answer the following questions? Whenever several answers are possible, give at least two.
1. ?- f( s(1), A).
A = two.
2. ?- f( s(s(1)), two).
False.
3. ?- f( s(s(s(s(s(s(1)))))), C).
C=two.
4. ?- f( D, three).
D = s(s(1)) ;
D = s(s( s(s(s(s(s(X)))))));
5. ?- f(A,B).
A = 1,
B = one ;
A = s(1),
B = two ;
6. ?-f(s(X),1).
Error.
7. ?- f(1,N).
N=one.