Fix missing formatting of "T"

chapters/functions.tex

@@ -2108,7 +2108,7 @@ \subsubsection{Arrays}\label{arrays-1}
 
 The method used to pass array arguments to FORTRAN~77 functions in the absence of an explicit external function call is similar to the one defined above for C: first the address of the array, then the dimension sizes as integers.
 See the table below.
-The type T is allowed to be any of the simple types which can be passed to FORTRAN~77 as defined in \cref{simple-types} and it is mapped to the type $T'$ as defined in that section.
+The type \lstinline!T! is allowed to be any of the simple types which can be passed to FORTRAN~77 as defined in \cref{simple-types} and it is mapped to the type $T'$ as defined in that section.
 
 \begin{center}
 \begin{tabular}{l|l}