Fixed typo in isometry proof.

src/measure/radon/c0.tex

@@ -62,7 +62,7 @@
 
     so
     \[
-    \abs{\int \phi d\mu} \le \sum_{j = 1}^n |\mu(A_j)| + 2n\eps
+    \abs{\int \phi d\mu} \ge \sum_{j = 1}^n |\mu(A_j)| - 2n\eps
     \]
 
     As such a $\phi$ exists for all $\eps > 0$, $\norm{I_\mu}_{C_0(X; \complex)} \ge \sum_{j = 1}^n |\mu(A_j)|$. Since this holds for all such partitions, $\norm{I_\mu}_{C_0(X; \complex)} \ge |\mu|(X)$. Therefore the map $\mu \mapsto I_\mu$ is isometric.