pretty([H|T], I) :- !,
	J is I + 3,
	pretty(H, J),
	prettyx(T, J),
	nl.
pretty(X, I) :-
	tab(I),
	print(X).

prettyx([], _).
prettyx([H|T], I) :-
	pretty(H, I),
	prettyx(T, I).

run :- pretty([1,2,[3,4],5,6], 0).
