// element occurrences in list

static int countOccurrencesIC(Collection<S> c, S x) {

  int n = 0;

  if (c != null) for (S o : c)

    if (eqic(x, o))

      ++n;

  ret n;

}

// string occurrences in string (not counting overlapping)

static int countOccurrencesIC(S s, S x) {

  int i = 0, nx = l(x), count = 0;

  if (nx == 0) ret 0;

  while ((i = indexOfIC(s, x, i)) >= 0) {

    ++count;

    i += nx;

  }

  ret count;

}