On a nonempty compact Hausdorff space, let continuous nonnegative functions decrease pointwise. Their suprema decrease to a finite number . For every , the sets are nonempty nested closed sets; compactness gives a common point with limit value at least . Thus the supremum of the pointwise limit is . The limit need not be continuous, and this conclusion does not claim uniform convergence as in the Dini theorem.
Uniform algebra 2026-10-14
A uniform algebra on a compact Hausdorff space is a closed complex subalgebra of , with the supremum norm, containing the constants and separating points. Evaluation embeds continuously and injectively in the character space of an algebra. The embedding is a homeomorphism onto a closed subset because its domain is compact and its target is Hausdorff. Extra characters need not be point evaluations on the specified .