Definition:Cover of Set/Subset

Definition
Let $S$ be a set. Let $T \subseteq S$ be a subset.

Let $\CC$ be a set of subsets of $S$.

Then $\CC$ is a cover of $T$ $A \subseteq \ds \bigcup \CC$, where $\cup$ denotes union.

Also see

 * Definition:Open Cover of Subset