% From the book
% PROLOG PROGRAMMING IN DEPTH
% by Michael A. Covington, Donald Nute, and Andre Vellino
% (Prentice Hall, 1997).
% Copyright 1997 Prentice-Hall, Inc.
% For educational use only

% File FIB.PL
% Computes Fibonacci numbers the inefficient way.

fib(1,1) :- !.
fib(2,1) :- !.
fib(N,F) :- N>2,
            N1 is N-1, fib(N1,F1),
            N2 is N-2, fib(N2,F2),
            F is F1+F2.