static bool lispEqic(Lisp a, Lisp b) {
  if (a == null) ret b == null;
  if (neqic(a.head, b.head)) false;
  int n = l(a.args);
  if (n != l(b.args)) false;
  for i to n:
    if (!lispEqic(a.args.get(i), b.args.get(i))) false;
  true;
}

static bool lispEqic(Lisp a, S b) {
  if (a == null) ret b == null;
  ret nempty(a.args) && eqic(a.head, b);
}