Programiranje 13/09/2016 recursion

suma(1, 1).
suma(N, S):- N>0, N1 is N-1, suma(N1, S1), S is S1+N.
fakt(1, 1).
fakt(N, F):- N>0, N1 is N-1, fakt(N1, F1), F is F1*N.
fib(1, 1).
fib(2, 1).
fib(N, F):- N>2, N1 is N-1, N2 is N-2, fib(N1, F1), fib(N2, F2), F is F1+F2.