Countable Particular Point Space is Lindelöf

Theorem
Let $T = \left({S, \vartheta_p}\right)$ be a countable particular point space.

Then $T$ is a Lindelöf apace.

Proof
Consider the open cover of $T$:
 * $\mathcal C = \left\{{\left\{{x, p}\right\}: x \in S, x \ne p}\right\}$

As $S$ is countable, then so is $\mathcal C$, as we can set up a bijection from $\phi: S \setminus \left\{{p}\right\} \leftrightarrow \mathcal C$:
 * $\forall x \in S \setminus \left\{{p}\right\}: \phi \left({x}\right) = \left\{{x, p}\right\}$

Hence $\mathcal C$ is its own countable subcover.

The result follows by definition of Lindelöf apace.