Remove vertical lines in operator precedence table

chapters/operatorsandexpressions.tex

@@ -41,7 +41,7 @@ \section{Operator Precedence and Associativity}\label{operator-precedence-and-as
 % Beware that the array construction operator, normally expressed as \lstinline!{ }! needs escaped braces inside \caption.
 \caption{Operators in order of precedence from highest to lowest, as derived from the Modelica grammar in \cref{modelica-concrete-syntax}.  All operators are binary except the postfix operators and those shown as unary together with \emph{expr}, the conditional operator, the array construction operator \lstinline!\{ \}! and concatenation operator \lstinline![ ]!, and the array range constructor which is either binary or ternary.  Operators with the same precedence occur at the same table row.}\label{tab:operator-precedence}
 \begin{center}
-\begin{tabular}{l|l|l}
+\begin{tabular}{l l l}
 \hline
 \tablehead{Operator group} & \tablehead{Operator syntax} & \tablehead{Examples}\\
 \hline