Product Space is T3 1/2 iff Factor Spaces are T3 1/2

Theorem
Let $\mathbb S = \family {\struct{S_\alpha, \tau_\alpha} }_{\alpha \mathop \in I}$ be an indexed family of topological spaces for $\alpha$ in some indexing set $I$ with $S_\alpha \neq \O$ for every $\alpha \in I$.

Let $\displaystyle T = \struct{S, \tau} = \displaystyle \prod_{\alpha \mathop \in I} \struct{S_\alpha, \tau_\alpha}$ be the product space of $\mathbb S$.

Then $T$ is a $T_{3 \frac 1 2}$ space each of $\struct{S_\alpha, \tau_\alpha}$ is a $T_{3 \frac 1 2}$ space.