Polished A-A and added new lines for broken enumerates.

src/measure/sets/elementary.tex

@@ -8,7 +8,8 @@
         \item[(P1)] $\emptyset \in \ce$.
         \item[(P2)] For any $A, B \in \ce$, $A \cap B \in \ce$.
         \item[(E)] For any $E, F \in \ce$ with $E \subset F$, there exists $\seqf{E_j} \subset \ce$ such that $E \setminus F = \bigsqcup_{j = 1}^n E_j$.
-    \end{enumerate}
+    \end\{enumerate\}
+
     If $X \in \ce$, then (E) may be replaced with
     \begin{enumerate}
         \item[(E')] For any $E \in \ce$, there exists $\seqf{E_j} \subset \ce$ such that $E^c = \bigsqcup_{j = 1}^n E_j$.