Fix typo (3 times): 'A' -> 'a'

This typo is a regression from 3.4.

chapters/overloaded.tex

@@ -63,7 +63,7 @@ \section{Matching Function}\label{matching-function}
 function f
   input $A_1$ $u_1$;
   $\ldots$
-  input $A_{m}$ $u_{m}$ := $A_{m}$;
+  input $A_{m}$ $u_{m}$ := $a_{m}$;
   $\ldots$
   input $A_{n}$ $u_{n}$;
   output B y;
@@ -73,10 +73,10 @@ \section{Matching Function}\label{matching-function}
 \end{lstlisting}
 
 The vector $P$ indicates whether argument $m$ of \lstinline!f! has a default value (\lstinline!true! for default value, \lstinline!false! otherwise).
-A call \lstinline!f($A_1$, $a_{2}$, $\ldots$, $a_{k}$, $b_{1}$ = $w_{1}$, $\ldots$, $b_{p}$ = $w_{p}$)! with distinct names $b_{j}$ is a valid match for the function \lstinline!f!, provided (treating \lstinline!Integer! and \lstinline!Real! as the same type)
+A call \lstinline!f($a_1$, $a_{2}$, $\ldots$, $a_{k}$, $b_{1}$ = $w_{1}$, $\ldots$, $b_{p}$ = $w_{p}$)! with distinct names $b_{j}$ is a valid match for the function \lstinline!f!, provided (treating \lstinline!Integer! and \lstinline!Real! as the same type)
 \begin{itemize}
 \item
-  $A_{i}$ = typeOf($A_{i}$) for $1 \leq i \leq k$,
+  $A_{i}$ = typeOf($a_{i}$) for $1 \leq i \leq k$,
 \item
   the names $b_{j}$ = $u_{Q_{j}}$, $Q_{j} > k$, $A_{Q_{j}}$ = typeOf($w_{j}$) for $1 \leq j \leq p$, and
 \item