Particular Point Space is Path-Connected

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

Then $T$ is path-connected.

Proof
Let $q \in S$.

Let $I$ be the (closed) unit interval in $\R$.

Let $f: I \to S$ be the mapping defined as:
 * $\forall x \in I: f \left({x}\right) = \begin{cases}

p & : x \in \left[{0. . 1}\right) \\ q & : x = 1 \end{cases}$

Suppose $U \in \vartheta_p$.

Then either $q \in U$ or $q \notin U$.

If $q \in U$ then $f^{-1} \left({U}\right) = \left[{0. . 1}\right]$ which is open in $I$ because $\left[{0. . 1}\right] = I$.

If $q \notin U$ then $f^{-1} \left({U}\right) = \left[{0. . 1}\right)$ which is half open in $\R$ but open in $I$.

So $f: I \to S$ is a continuous mapping and so a path from $p$ to $q$.

As $q$ is any point in $S$ it follows that $T$ is path-connected.