Cover

Definition

An arbitrary family of sets, [ilmath]\{S_\alpha\}_{\alpha\in I}[/ilmath] is said to cover another set, [ilmath]X[/ilmath] if:

• [math]X\subseteq\bigcup_{\alpha\in I}S_\alpha[/math], that is to say that:
• [ilmath]X[/ilmath] is contained in the union of the members of the family.

See also

• Sub-cover
• Compactness