Let $X$ be a non-empty set and $I$ a collection of some nested subsets of $X$ indexed by a linearly ordered set $(\Lambda,\le)$ such that $I$ always contains the void set $\emptyset$ and the whole set $X$, i.e. $$I=[\{\emptyset,A_\lambda,X:A_\lambda\subset X,\lambda\in\Lambda\}]$$ such that $A_\alpha\subset A_\beta$ whenever $\alpha\le\beta$. It is easy to show that $I$ qualifies as a topology on $X$. under what condition this chain topology will be compact?