seq(from = -2, to = 2, by = 1)
seq(from = -2, to = 2, by = 0)
seq(from = -2, to = 2, by = -1)
seq(from = -2, to = 2, by = 10)
seq(from = 2, to = -2, by = 1)
seq(from = 2, to = 2, by = 1)
seq(from = 2, to = 2, by = -1)
seq(from = 2, to = 2, by = 0)
seq(from = 0, to = 0, by = 0)