static S clUnparse(Lisp l) {
  if (l == null) ret "";
  ret join(" ", (L) concatLists(ll(conceptQuote(l.head)), map(f clUnparse_sub, l)));
}

static S clUnparse_sub(Lisp l) {
  ret l.empty() ? clUnparse(l) : "(" + clUnparse(l) + ")";
}

static L<S> clUnparse(L<Lisp> l) {
  ret map(f clUnparse, l);
}