main =>
  Num is 1_000_000,
  statistics(runtime,[Start|_]),
  PrimeList = primes(Num),
  NumPrimes = PrimeList.len,
  statistics(runtime,[Stop|_]),
  RunTime = Stop - Start,
  printf("There are %w primes until %w [time(ms) %w]%n",NumPrimes, Num, RunTime),
  DiffList = [[1], [2], [2,2], [2,4], [4,2], [2,4,6],
              [2,6,4], [4,2,6], [4,6,2], [6,2,4], [6,4,2],[6,4,2,4]],
  run(DiffList, PrimeList).

primesByDiffs([],_,[]).
primesByDiffs([Prime|Primes], Diff, [Slide|Slides]):-
  Slide = new_list(Diff.len+1),
  append(Slide, _, [Prime|Primes]),
  select(Diff, Slide),!,
  primesByDiffs(Primes, Diff, Slides).
primesByDiffs([_|Primes], Diff, Slides):-
  primesByDiffs(Primes, Diff, Slides).

select([],_).
select([Diff|Diffs],[S1, S2|Stail]):-
  S2 = S1 + Diff,
  select(Diffs, [S2|Stail]).

run([],_).
run([Diff|Dtail], PrimeList):-
  statistics(runtime,[Start|_]),
  primesByDiffs(PrimeList, Diff, SlideList),	
  Num = SlideList.len,
  statistics(runtime,[Stop|_]),
  Runtime = Stop - Start,
  printf("%-10w number: %5w (%2wms) first: %-22w last: %-22w\n", Diff, Num, Runtime, SlideList.first, SlideList.last),
  !,
  run(Dtail, PrimeList).