static L<S> endingWithIC(Collection<S> l, fS suffix) {
  new L<S> out;
  for (S s : unnull(l))
    if (ewic(s, suffix))
      out.add(s);
  ret out;
}

static L<S> endingWithIC(S suffix, Collection<S> l) {
  ret endingWithIC(l, suffix);
}