static L<IntRange> findNCNNonStreaks(L l, F1<LS, Bool> pred) {
  new L<IntRange> out;
  int i = 1, n = l(l);
  while (i < n) {
    int j = i;
    while (j < n && !isTrue(callF(pred, subList(l, j-1, j+2)))) j += 2;
    if (j > i)
      out.add(intRange(i, j-1));
    i = j+2;
  }
  ret out;
}