Definition: A space $X$ is $\Delta$-normal if for every $A \subset X^2 \setminus \Delta_X$ closed in $X^2$ there exist disjoint open $U$ and $V$ in $X^2$ such that $A \subset U$ and $\Delta_X \subset V$, where $\Delta_X$ is the diagonal of $X$, i.e., $\{(x,x): x\in X\}$.
Is Mrowka space $\Delta$-normal?
Thanks for your help.