/**/
fib(0, [0]).
fib(1, [1,0]).
fib(N, [R, X, Y | Zs]) :-
	N > 1,
	N1 is N - 1,
	fib(N1, [X, Y | Zs]),
	R is X + Y.

% wrong naive impl
reverse([], []).
reverse([x], [x]).
reverse([Head|Tail], [RNew, Head]) :-
	reverse(Tail, RNew).

accrev([H|T], Acc, R) :-
	accrev(T, [H|Acc], R).
accrev([], R, R).

rev(L, R) :- accrev(L, [], R).

smol([S], S).
smol([H|T], S) :-
	smol(T, Snew),
	Snew < H -> S is Snew; S is H.

% not working
accsortt([], Acc, Acc).
accsortt([H1 | T], Acc, R) :-
	H2 | T,
	H1 < H2
	-> accsortt(T, [H1, H2 | Acc], R);
	accsortt(T, [H2, H1 | Acc], R).

sortt(L, R) :- accsortt(L, [], R).