id = 126
group = 'sorting'
number = 33
visible = True
facts = None

solution = '''\
del126(X, [X|T], T).
del126(X, [Y|T], [Y|L]) :-
  del126(X, T, L).

permute126([], []).
permute126(L, [X|P]) :-
  del126(X, L, L1),
  permute126(L1, P).

is_sorted126([_]).
is_sorted126([H1,H2|T]) :-
  H1 =< H2,
  is_sorted126([H2|T]).

slowest_sort_ever(L, S) :-
  permute126(L, S),
  is_sorted126(S).
'''