static L<S> startingWithIC_wordBoundary(Iterable<S> l, fS prefix) {
  ret [S s : unnull(l) | swic_wordBoundary(s, prefix)];
}

static L<S> startingWithIC_wordBoundary(S prefix, Iterable<S> l) {
  ret startingWithIC_wordBoundary(l, prefix);
}