\subsection*{Appendix}

Figure~\ref{insert-rdwr} illustrates the sort of machine
code appropriate for the processors of the proposed computer
system model. This code corresponds to the dataflow signal
graph for the {\tt Insert} function given in Figure~\ref{insert-dfg}.
We hope that the code is mostly self-explanatory.
The symbol {\tt A} is a reference to the argument structure
(a tuple of values) for the function. 
Names such as {\tt m} and {\tt n} denote offsets from the
base of a data frame, and are candidates for loading into
registers in optimized machine code. An instruction
such as {\tt READ A+0, c2} means read from the location
with address equal to the argument pointer plus zero, and
send the value with a signal to the instruction labelled
{\tt c2}, which must be a {\tt RECEIVE} instruction that
stores the value. The form {\tt RECEIVE(2)} simply means that two signals
must be sent to the instruction before it becomes enabled.
The {\tt APPLY} instruction has three arguments: a pointer
to the function to be applied, the argument pointer, and a
continuation specifier (label) that indicates where activity
should be enabled upon termination.
The code is grouped into blocks of instructions where
each block constitutes a {\em thread} that can always complete
without waiting for any response from the memory system.

\begin{figure}[tb]\footnotesize
\begin{center}

\illustrationx{insert-code}{4in}

\end{center}
\caption{\label{insert-rdwr}Multithreaded code for
   the {\tt Insert} function.}
\end{figure}




