(−∞,∞)−{−1}(-\infty, \infty)-\{-1\}(−∞,∞)−{−1}
(−∞,∞)−{1}(-\infty, \infty)-\{1\}(−∞,∞)−{1}
(0,∞)(0, \infty)(0,∞)
(−∞,∞)(-\infty, \infty)(−∞,∞)
