We say that a topological space $X$ is:

- $AB$, provided that $X$ is $T_1$ and for each pair $(A, B)$ of compact, disjoint subsets of $X$ there is $U$, an open subset of $X$, such that either $A \subseteq U$ and $U \cap B = \varnothing$ or $B \subseteq U$ and $U \cap A = \varnothing$.
- $US$, provided that convergent sequences have a unique limit.

I would like to know an example of a topological space that is $US$ but not $AB$.

Thanks