[IA] - F3

%somatorio
somatorio(1,1).
somatorio(N,S):- N1 is N-1,somatorio(N1,S1), S is S1+N.
%factorial
factorial(0,1).
factorial(N,S):- N1 is N-1,factorial(N1,S1), S is S1*N.
%comprimento
comprimento([],0).
comprimento([_|Cauda],S):-comprimento(Cauda,S1),S is S1+1.

n_elemento(1,[C|_],C).
n_elemento(X,[_|Cauda],N):-X1 is X-1,n_elemento(X1,Cauda,N).

potencia(B,1,B).
potencia(B,N,P):-N1 is N-1,potencia(B,N1,P1),P is P1*B.

%max(X,Y,Max):-X>Y -> Max is X ; Max is Y.
%OU
max(X,Y,X):-X>=Y,!.
max(_,Y,Y).

%maxlista([C],C).
%maxlista([C|Cauda],X):-maxlista(Cauda,X1),C>X1 -> X is C ; X is X1.
%OU
maxlista([C],C):-!.
maxlista([C|Cauda],X):-maxlista(Cauda,X1),max(C,X1,X).