Require that equalityConstraint dimension is constant Integer

Also rephrasing a bit to avoid some repetition.

chapters/connectors.tex

@@ -813,7 +813,9 @@ \subsection{Overconstrained Equation Operators for Connection Graphs}\label{over
   end equalityConstraint;
 end Record;
 \end{lstlisting}
-The \lstinline!residue! output of the \lstinline!equalityConstraint! function shall have known size, say constant $n$.  The function shall express the equality between the two type instances \lstinline!T1! and \lstinline!T2! or the record instances \lstinline!R1! and \lstinline!R2!, respectively, with a non-redundant number $n \ge 0$ of equations.  The residues of these equations are returned in vector \lstinline!residue! of size $n$.  The set of $n$ non-redundant equations stating that \lstinline!R1 = R2! is given by the equation (\lstinline!0! represents a vector of zeros of appropriate size):
+The array dimension $n$ of \lstinline!residue! shall be a constant \lstinline!Integer! expression that can be evaluated during translation, with $n > 0$.
+The \lstinline!equalityConstraint! expresses the equality between the two type instances \lstinline!T1! and \lstinline!T2! or the record instances \lstinline!R1! and \lstinline!R2!, respectively, as the $n$ non-redundant equation residuals returned in \lstinline!residue!.
+That is, the set of $n$ non-redundant equations stating that \lstinline!R1 = R2! is given by the equation (\lstinline!0! represents a vector of zeros of appropriate size):
 \begin{lstlisting}[language=modelica]
   Record R1, R2;
 equation