Every nonempty bounded-above subset of $\RR$ has a supremum, and every bounded-below one an infimum.Suggest a slogan
Let \(A\subseteq\RR\) be nonempty. If \(A\) is bounded above, then \(A\) has a supremum \(\sup A\in\RR\); if \(A\) is bounded below, then \(A\) has an infimum \(\inf A\in\RR\).