1.8 Show that the following classes all generate the Borel -algebra, or, put differently, show the equality...

1.8 Show that the following classes all generate the Borel σ-algebra, or, put differently, show the equality of the following collections of sets:

σ (

(a,

b) : a

b) : b ∈ R)

= σ ((−∞,

b) : b ∈ Q), where Q is the set of rational numbers.