Supremum of Negative is Negative of InfimumLast updated Nov 1, 2022# StatementLet $A \subset \bar{\mathbb{R}}$. Denote $-A = {-a : a \in A}$. Then $$\sup(-A) = -\inf A$$# ProofTODO# Other OutlinksExtended Real NumbersSetSupremumInfimum