static LS words2_notNextToNumbers_plusApostrophe(S s) {
  new L<S> l;
  int n = l(s);
  for (int i = 0; i < n; ) {
    if (isDigit(s.charAt(i))) continue with ++i;
    int j = i;
    while (j < n && isLetterOrApostrophe(s.charAt(j)))
      ++j;
    if (j < n && isDigit(s.charAt(j))) continue with i = j;
    if (j > i) l.add(substring(s, i, j));
    while (j < n && !isLetterOrApostrophe(s.charAt(j)))
      ++j;
    i = j;
  }
  ret l;
}