diff --git a/Books/BabyRudin/Chapter01/ex05.gapry.tex b/Books/BabyRudin/Chapter01/ex05.gapry.tex new file mode 100644 index 0000000..583f06f --- /dev/null +++ b/Books/BabyRudin/Chapter01/ex05.gapry.tex @@ -0,0 +1,14 @@ +\subsection*{Exercise 05 (Gapry)} +\begin{flushleft} +$\text{(1) } \exists\ \alpha \in R \ni x \geq \alpha \ \forall x \in A$ \\ +$\text{(2) } \exists\ \alpha \in R \ni -x \leq -\alpha \ \forall -x \in -A$ \\ +\end{flushleft} + +\begin{flushleft} +(1) $\implies \alpha = \inf( A)$ \\ +(2) $\implies -\alpha = \sup(-A)$ +\end{flushleft} + +\begin{flushleft} +Obviously, $a = -(-a) \implies \inf(A) = -\sup(-A)$ +\end{flushleft}