Show that $\mathbb{Q}$ with the topology induced by the Sorgenfrey line is normal.
Here, the Sorgenfrey line is the line with the topology whose basis are formed as:
$$\{[a,b) : a < b \}$$
I know that, assuming that it is not normal, I have to show that for any two closed sets, every pair of open sets containing each one of them has to be non trivial. How to do this?