1 1 ------ <= ---------- x x + 1 3 + 5 3 - 1
1/(3^x + 5) <= 1/(3^(x + 1) - 1)
And(x <= 1, -1 < x)
(x <= 1)∧(-1 < x)
(-1, 1]
x in Interval.Lopen(-1, 1)