Cork Institute of Technology
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Bachelor of Science (Honours) in Computer Applications - Award
(Bachelor of Science in Computer Applications – Award)
(NFQ – Level 8)
Autumn 2005
Artificial Intelligence
(Time: 3 Hours)
Answer question any FOUR questions
(All questions carry equal marks).
Examiners: Mr. P. Rothwell
Mr. E. A. Parslow
Mr. P. O Connor
Dr. D. Chambers
1. (a) Using the following program and query as an example write a general
description of Prolog in terms of its syntax, list handling, and the use of
recursion. Include a brief description of the effect of this program.
prog( _, [] ,[]).
prog(L2, [ X | L1], [ X | L3 ]):- member(X, L2), prog(L2, L1, L3),!.
prog(L2,[ _ | L1], L3):- prog(L2, L1, L3),!.
?- prog([p, f, d, a, g, c], [ a, p, b, q, c, r], L). [10 marks]
(b) The following Prolog program can be used to solve the N-Queens problem:
%gen(X,Y,L) generates a list L of numbers from X to Y
nqs(N,S):- gen(1,N,Dxy), Nu1 is 1-N, Nu2 is N-1, gen(Nu1,Nu2,Du),
Nv2 is N+N, gen(2,Nv2,Dv), sol(S,Dxy,Dxy,Du,Dv).
Sol([],[],Dy,Du,Dv).
Sol([Y|Ylist],[X|Dx1],Dy,Du,Dv):-
del(Y,Dy,Dy1), U is X-Y, del(U,Du,Du1), V is X+Y,
del(V,Dv,Dv1), sol(Ylist,Dx1,Dy1,Du1,Dv1).
In your own words, explain how the above program would try to generate a
solution S for the four queens problem. Include an explanation of each line
(refer to line numbers) of the program in terms of the representation being
used. [10 marks]
(c) Write and fully explain a Prolog program to define the predicate
intersect(A, B, C) which assigns to the list C the intersection of the lists A and
B (you may use system defined predicates):.
E.g. ?- intersect([a,b,c], [d,e,b,c], L).
L=[b,c] [5 marks]
[Total: 25 marks]
