Fix 'if of type' -> 'is of type'

chapters/synchronous.tex

@@ -576,7 +576,9 @@ \subsection{Base-clock conversion operators}\label{base-clock-conversion-operato
 
 Input argument $u$ can be a general expression, because the argument is continuous-time and therefore has always a value.  It can also be a constant, a parameter or a piecewise constant expression.
 
-Note that \lstinline!sample! is an overloaded function:  If \lstinline!sample! has two positional input arguments and the second argument is of type \lstinline!Real!, it is the operator from \cref{event-related-operators-with-function-syntax}.  If \lstinline!sample! has one input argument, or it has two input arguments and the second argument if of type \lstinline!Clock!, it is the base-clock conversion operator from this section.
+Note that \lstinline!sample! is an overloaded function:
+If \lstinline!sample! has two positional input arguments and the second argument is of type \lstinline!Real!, it is the operator from \cref{event-related-operators-with-function-syntax}.
+If \lstinline!sample! has one input argument, or it has two input arguments and the second argument is of type \lstinline!Clock!, it is the base-clock conversion operator from this section.
 \end{nonnormative}
 \end{semantics}
 \end{operatordefinition*}