(−∞,0](-\infty, 0](−∞,0]
(−∞,0)(-\infty, 0)(−∞,0)
(−∞,1](-\infty, 1](−∞,1]
(−∞,1)(-\infty, 1)(−∞,1)
[0,∞)[0, \infty)[0,∞)