static void thoughtSpaceSizePrinter() {
  final AbstractThoughtSpace ts = thoughtSpace();
  doEvery_daemon(1000, new Runnable {
    int n = ts.size();
    public void run() {
      int _n = ts.size();
      if (_n != n)
        print("Thought space size: " + (n = _n));
    }
  });
}