improve wording

Author: vladak

proc.tex

@@ -593,9 +593,10 @@
 to the process address space.  The loader then maps all dynamic libraries there
 as well, then finally calls the program \texttt{main()}.
 \item A useful exercise is to write a simple program calling \texttt{open()},
-for example.  When done, run the program via \texttt{truss(1)} or
-\texttt{strace(1)} like this: \texttt{truss ./a.out}. You will see what is being
-done before \texttt{open} is called in the end.
+for example.  Then run the program via \texttt{truss(1)} or
+\texttt{strace(1)} like this: \texttt{truss ./a.out}. You will see a number of
+system calls before \texttt{open} is actually called. These system calls
+can be attributed to the dynamic linker.
 \item The \texttt{FD\_CLOEXEC} file descriptor flag is set using the
 \texttt{fcntl} system call. It can be also set via implementation specific
 (i.e. non-standard) way, e.g. by passing the \texttt{O\_CLOEXEC} flag to