{(−4,0),(4,0)}\{(-4,0),(4,0)\}{(−4,0),(4,0)}
{(4,0)}\{(4,0)\}{(4,0)}
{(0,4)}\{(0,4)\}{(0,4)}
{(−4,0),(4,4)}\{(-4,0),(4,4)\}{(−4,0),(4,4)}