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\begin{document}

\handout{errata}{Parallel Computation Notes Errata}{May 8, 1992}

\medskip

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
This handout is a correction of some bugs in Handout 54, the
supplementary reading on parallel computation.  ``Line $-k$'' means
``the $k$th line from the bottom''.

\begin{itemize}

\item p. 7, line -1:  The matrix elements $A_{i,j}$ and $B_{j,k}$ are missing
their commas.

\item p. 8, line 12:  The element of $C$ should be $C_{i,k}$.

\item p. 9, lines -11 to -3:  This optimization appears to be incorrect.
Please just delete it.

\item p. 15, lines -10 and -9:  The statement of Corollary 1 is slightly
garbled.  The bound on the number of processors and the global space
should be $2^{c S^2(n)}$ for some constant $c$ (and that applies to
the local space as well).  Also, the bound on the time should be
$O(S^2(n))$, not ``polynomial in $O(S(n))$''.

\item p. 16:  In the statement of Theorem 3, the ``step-counting'' condition
might not be exactly what is needed here.  This will need fixing on
another pass through the notes.  For now, just realize that the
simulation requires some complexity bound for computing the required
functions.
(You won't have to figure this out on the final.)

\item p. 19, line -12: The circuit should be $B_n$.

\item p. 22, line 16: ``in parallel time $O(S(n))$''

\item p. 22, line -8: ``the same function as $\cal B$''

\end{itemize}





\end{document}
