fix wording

network.tex

@@ -210,8 +210,9 @@
 network related functions from the previous slide.
 \item Sockets use the same name space as file descriptors, i.e. the same
 descriptor table.  If you write a simple program that only calls
-\funnm{socket}(), it will return 3 as that will be the first available slot in
-the descriptor table.
+\funnm{socket}(), it will return the same file descriptor number as if
+\funnm{open()} was called, i.e. the first available slot in the descriptor
+table, usually 3.
 \item Connection-oriented communication is always bidirectional and is similar
 to pipes.  However, note that pipes may not be bidirectional, see page
 \pageref{TWO_WAY_PIPES}.