\typeout{Document Style 'LCSletter'. Version 1.0 - released 12/12/89}
% Version 1.0 by David Jones, based on earlier work by persons unknown
\def\@ptsize{0} \@namedef{ds@11pt}{\def\@ptsize{1}}
\@namedef{ds@12pt}{\def\@ptsize{2}} 
\@twosidefalse
\def\ds@draft{\overfullrule 5pt} 
\@options
\lineskip 1pt \normallineskip 1pt
\def\baselinestretch{1}
\ifcase \@ptsize\relax 
\def\@normalsize{\@setsize\normalsize{12pt}\xpt\@xpt 
\abovedisplayskip 10pt plus2pt minus5pt\belowdisplayskip \abovedisplayskip
\abovedisplayshortskip \z@ plus3pt\belowdisplayshortskip 6pt plus3pt minus3pt}
\def\small{\@setsize\small{11pt}\ixpt\@ixpt
\abovedisplayskip 8.5pt plus 3pt minus 4pt\belowdisplayskip \abovedisplayskip
\abovedisplayshortskip \z@ plus2pt\belowdisplayshortskip 4pt plus2pt minus 2pt}
\def\footnotesize{\@setsize\footnotesize{9.5pt}\viiipt\@viiipt
\abovedisplayskip 6pt plus 2pt minus 4pt\belowdisplayskip \abovedisplayskip
\abovedisplayshortskip \z@ plus 1pt\belowdisplayshortskip 3pt plus 1pt minus
2pt}
\def\scriptsize{\@setsize\scriptsize{8pt}\viipt\@viipt}
\def\tiny{\@setsize\tiny{6pt}\vpt\@vpt}
\def\large{\@setsize\large{14pt}\xiipt\@xiipt}
\def\Large{\@setsize\Large{18pt}\xivpt\@xivpt}
\def\LARGE{\@setsize\LARGE{22pt}\xviipt\@xviipt}
\def\huge{\@setsize\huge{25pt}\xxpt\@xxpt}
\def\Huge{\@setsize\Huge{30pt}\xxvpt\@xxvpt}
\or 
\def\@normalsize{\@setsize\normalsize{13.6pt}\xipt\@xipt
\abovedisplayskip 11pt plus3pt minus6pt\belowdisplayskip \abovedisplayskip
\abovedisplayshortskip \z@ plus3pt\belowdisplayshortskip 6.5pt plus3.5pt
minus3pt}
\def\small{\@setsize\small{12pt}\xpt\@xpt
\abovedisplayskip 10pt plus2pt minus5pt\belowdisplayskip \abovedisplayskip
\abovedisplayshortskip \z@ plus3pt\belowdisplayshortskip 6pt plus3pt minus3pt}
\def\footnotesize{\@setsize\footnotesize{11pt}\ixpt\@ixpt
\abovedisplayskip 8pt plus 2pt minus 4pt\belowdisplayskip \abovedisplayskip
\abovedisplayshortskip \z@ plus 1pt\belowdisplayshortskip 4pt plus 2pt minus
2pt}
\def\scriptsize{\@setsize\scriptsize{9.5pt}\viiipt\@viiipt}
\def\tiny{\@setsize\tiny{7pt}\vipt\@vipt}
\def\large{\@setsize\large{14pt}\xiipt\@xiipt}
\def\Large{\@setsize\Large{18pt}\xivpt\@xivpt}
\def\LARGE{\@setsize\LARGE{22pt}\xviipt\@xviipt}
\def\huge{\@setsize\huge{25pt}\xxpt\@xxpt}
\def\Huge{\@setsize\Huge{30pt}\xxvpt\@xxvpt}
\or 
\def\@normalsize{\@setsize\normalsize{15pt}\xiipt\@xiipt
\abovedisplayskip 12pt plus3pt minus7pt\belowdisplayskip \abovedisplayskip
\abovedisplayshortskip \z@ plus3pt\belowdisplayshortskip 6.5pt plus3.5pt
minus3pt}
\def\small{\@setsize\small{13.6pt}\xipt\@xipt
\abovedisplayskip 11pt plus3pt minus6pt\belowdisplayskip \abovedisplayskip
\abovedisplayshortskip \z@ plus3pt\belowdisplayshortskip 6.5pt plus3.5pt
minus3pt}
\def\footnotesize{\@setsize\footnotesize{12pt}\xpt\@xpt
\abovedisplayskip 10pt plus2pt minus5pt\belowdisplayskip \abovedisplayskip
\abovedisplayshortskip \z@ plus3pt\belowdisplayshortskip 6pt plus3pt minus3pt}
\def\scriptsize{\@setsize\scriptsize{9.5pt}\viiipt\@viiipt}
\def\tiny{\@setsize\tiny{7pt}\vipt\@vipt}
\def\large{\@setsize\large{18pt}\xivpt\@xivpt}
\def\Large{\@setsize\Large{22pt}\xviipt\@xviipt}
\def\LARGE{\@setsize\LARGE{25pt}\xxpt\@xxpt}
\def\huge{\@setsize\huge{30pt}\xxvpt\@xxvpt}
\let\Huge=\huge
\fi
\normalsize 

\oddsidemargin 0pt \evensidemargin 0pt \marginparwidth 90pt \marginparsep
11pt \marginparpush 5pt 
\topmargin 27pt \headheight 12pt \headsep 45pt \footheight 12pt \footskip
25pt 
\textheight 505pt \textwidth 470pt \columnsep 10pt \columnseprule 0pt 
\raggedbottom 
\footnotesep 12pt \skip\footins 10pt plus 2pt minus 4pt 
\floatsep 12pt plus 2pt minus 2pt
\textfloatsep 20pt plus 2pt minus 4pt
\intextsep 12pt plus 2pt minus 2pt
\dblfloatsep 12pt plus 2pt minus 2pt
\dbltextfloatsep 20pt plus 2pt minus 4pt
\@maxsep 20pt
\@dblmaxsep 20pt
\@fptop 0pt plus 1fil
\@fpsep 8pt plus 2fil
\@fpbot 0pt plus 1fil
\@dblfptop 0pt plus 1fil
\@dblfpsep 8pt plus 2fil
\@dblfpbot 0pt plus 1fil

\def\letterheadwidth{7.5in}
\def\raisehead{0.9in}
\def\predateskip{8pt}
\def\headline#1{\hbox to \hsize{\hss\hbox to \letterheadwidth{#1}\hss}}
\def\letterhead{\mbox{}\vskip -\topmargin\vskip -\headsep\vskip -\raisehead{
\headline{\xpt\sc massachusetts institute of technology\hfil}
\vskip .72in % Changed from .65in -- DMJ
\headline{\xviipt\special{psfile=/local/logo.ps}\hfil Laboratory
for Computer Science\hfil} % \special added by DMJ
\kern -5pt %Was  \kern -7pt   -MAS
\headline{\vbox{\hrule height1.4pt width\letterheadwidth}}
\kern -3pt
\headline{\viiipt M.L. Dertouzos, Director 
\hfil R.L. Rivest and A. Vezza, Associate Directors
\hfil 545 Technology Square, Cambridge, Massachusetts 02139}
\ifx\faxnum\@empty\else % These 4 lines added by DMJ
\kern -4.0pt 
\headline{\viiipt\hfil Fax: \faxnum}
\fi
\kern -4.0pt %Was  \kern -4.8pt   -MAS
\headline{\viiipt\hfil\ifx\roomnum\@empty \else Room \roomnum,\hspace{.75em}\fi
                      \ifx\telephonenum\@empty Phone: (617) 253--\hbox to 2em{\hfil} % Word "Phone" added by DMJ
\else Phone: \telephonenum\fi} % Word "Phone" added by DMJ
\kern -4.0pt %Was  \kern -4.8pt   -MAS
\headline{\viiipt\hfil \ifx\netaddressaux\@empty \hbox to 2em{\hfil}
\else\netaddressaux\fi}
\vskip \predateskip}}

\newdimen\longindentation
\longindentation=.5\textwidth
\newdimen\indentedwidth
\indentedwidth=\textwidth
\advance\indentedwidth -\longindentation
\newdimen\closingindentation
\closingindentation=\longindentation
\def\opening#1{\ifx\@empty\fromaddress
\thispagestyle{firstpage} 
\letterhead
\vskip 1ex plus .5cm
\noindent\hspace*{\closingindentation}\today\par
\vskip 10ex plus 3cm minus 5ex
\else \thispagestyle{empty} 
\vskip 0pt plus 2cm
{\raggedleft\begin{tabular}{l}\ignorespaces\fromaddress \\*[2\parskip]
\today \end{tabular}\par}
\vskip 10ex plus 2cm
\fi
\vspace{2\parskip}
{\raggedright \toname \\ \toaddress \par}\vspace{2\parskip}
\noindent #1\par\nobreak}
\long\def\closing#1{\par\nobreak\vspace{\parskip}
\stopbreaks
\noindent\hspace*{\closingindentation}%
\parbox{\indentedwidth}{\raggedright\ignorespaces #1\\[6\parskip]
\ifx\@empty\fromsig 
\fromname
\else \fromsig \fi\strut}
\par}
\def\ps{\par\startbreaks}
\def\cc#1{\par\noindent
\parbox[t]{\textwidth}{\@hangfrom{\rm cc: }\ignorespaces #1\strut}\par}
\def\encl#1{\par\noindent
\parbox[t]{\textwidth}{\@hangfrom{\rm encl: }\ignorespaces #1\strut}\par}
\def\stopletter{\vskip 0pt plus 1fil}
\def\returnaddress{}
\newcount\labelcount
\def\startlabels{\labelcount=0 \baselineskip=0pt \lineskip=0pt
\pagestyle{empty}
\let\@texttop=\relax
\topmargin -50pt
\headsep 0pt
\oddsidemargin -35pt
\evensidemargin -35pt
\textheight 10in
\@colht\textheight \@colroom\textheight \vsize\textheight
\textwidth 550pt
\columnsep 25pt
\xpt
\baselineskip=0pt
\lineskip=0pt
\boxmaxdepth=0pt
\twocolumn\relax}
\def\mlabel#1#2{\setbox0\vbox{\parbox[b]{3.6in}{\strut\ignorespaces #2}}
\vbox to 2in{\vss \box0 \vss}}

\long\def\letter#1{\newpage
\c@page\@ne
\interlinepenalty=200 \@processto{#1}}
\def\endletter{\stopletter\@@par\pagebreak\@@par
\if@filesw 
\begingroup 
\def\protect{\string}
\let\\=\relax
\def\protect##1{\string##1\space}
\immediate\write\@auxout{\string\mlabel{\returnaddress}{\toname
\\\toaddress}}
\endgroup 
\fi}
\long\def\@processto#1{\@xproc #1\\@@@\ifx\toaddress\@empty 
\else \@yproc #1@@@\fi}
\long\def\@xproc #1\\#2@@@{\def\toname{#1}\def\toaddress{#2}}
\long\def\@yproc #1\\#2@@@{\def\toaddress{#2}}
\def\stopbreaks{\interlinepenalty \@M
\def\par{\@@par\nobreak}\let\\=\@nobreakcr
\let\vspace\@nobreakvspace}
\def\@nobreakvspace{\@ifstar{\@nobreakvspacex}{\@nobreakvspacex}}
\def\@nobreakvspacex#1{\ifvmode\nobreak\vskip #1\relax\else
\@bsphack\vadjust{\nobreak\vskip #1}\@esphack\fi}
\def\@nobreakcr{\vadjust{\penalty\@M}\@ifstar{\@xnewline}{\@xnewline}}
\def\startbreaks{\let\\=\@normalcr
\interlinepenalty 200\def\par{\@@par\penalty 200}}
\def\name#1{\def\fromname{#1}}
\def\signature#1{\def\fromsig{#1}}
\def\fromsig{}
\long\def\address#1{\def\fromaddress{#1}}
\def\fromaddress{}
\def\location#1{\def\fromlocation{#1}}
\def\fromlocation{}
\def\telephone#1{\def\telephonenum{#1}}
\def\extension#1{\def\telephonenum{(617) 253--#1}}
\def\telephonenum{}
\def\fax#1{\def\faxnum{#1}} % These two lines added by DMJ
\def\faxnum{(617) 258--8682}
\def\netaddress#1{\def\netaddressaux{#1}}
\def\netaddressaux{}
\def\room#1{\def\roomnum{#1}}
\def\roomnum{}
\def\document{\endgroup
\@colht\textheight \@colroom\textheight \vsize\textheight
\columnwidth\textwidth \@clubpenalty\clubpenalty
\if@twocolumn \advance\columnwidth -\columnsep 
\divide\columnwidth\tw@ \hsize\columnwidth \@firstcolumntrue 
\fi
\hsize\columnwidth \linewidth\hsize
\begingroup\@floatplacement\@dblfloatplacement\endgroup
\if@filesw \immediate\openout\@mainaux=\jobname.aux
\immediate\write\@mainaux{\string\startlabels\string\@startlabels}\fi
\def\do##1{\let ##1\@notprerr}
\@preamblecmds
\let\do\noexpand 
\@normalsize\everypar{}}
\def\enddocument{\newpage\begingroup 
\if@filesw \immediate\closeout\@mainaux 
\makeatletter\input \jobname.aux\clearpage
\fi\endgroup\deadcycles\z@\@@end}
\def\makelabels{\@fileswtrue}
\def\@startlabels{}

\def\@texttop{}% Replaces \ifnum\c@page=1\vskip 0pt plus .00006fil\relax\fi
\def\ps@headings{\def\@oddhead{\sl To \ignorespaces\toname \hfil \today
\hfil Page \thepage}\def\@oddfoot{}}
\def\ps@empty{\def\@oddhead{}\def\@oddfoot{}\def\@evenhead{}\def\@evenfoot{}}
\def\ps@firstpage{\def\@oddhead{}\def\@oddfoot{}
\def\@evenhead{}\def\@evenfoot{}}
\def\ps@plain{\def\@oddhead{}\def\@oddfoot{\rm\hfil\thepage
\hfil}\def\@evenhead{}\let\@evenfoot\@oddfoot}

\parskip .7em \parindent 0pt \topsep .4em \partopsep 0pt \itemsep .4em 
\@lowpenalty 51 \@medpenalty 151 \@highpenalty 301 
\@beginparpenalty -\@lowpenalty \@endparpenalty -\@lowpenalty \@itempenalty
-\@lowpenalty 

\leftmargini 2.5em
\leftmarginii 2.2em \leftmarginiii 1.87em \leftmarginiv 1.7em \leftmarginv 1em
\leftmarginvi 1em
\leftmargin\leftmargini
\labelwidth\leftmargini\advance\labelwidth-\labelsep
\labelsep 5pt
\parsep 0pt
\let\@listi\relax
\def\@listii{\leftmargin\leftmarginii
\labelwidth\leftmarginii\advance\labelwidth-\labelsep}
\def\@listiii{\leftmargin\leftmarginiii
\labelwidth\leftmarginiii\advance\labelwidth-\labelsep
\topsep .2em 
\itemsep \topsep}
\def\@listiv{\leftmargin\leftmarginiv
\labelwidth\leftmarginiv\advance\labelwidth-\labelsep}
\def\@listv{\leftmargin\leftmarginv
\labelwidth\leftmarginv\advance\labelwidth-\labelsep}
\def\@listvi{\leftmargin\leftmarginvi
\labelwidth\leftmarginvi\advance\labelwidth-\labelsep}
\def\labelenumi{\arabic{enumi}.} 
\def\theenumi{\arabic{enumi}} 
\def\labelenumii{(\alph{enumii})}
\def\theenumii{\alph{enumii}}
\def\p@enumii{\theenumi}
\def\labelenumiii{\roman{enumiii}.}
\def\theenumiii{\roman{enumiii}}
\def\p@enumiii{\theenumi(\theenumii)}
\def\labelenumiv{\Alph{enumiv}.}
\def\theenumiv{\Alph{enumiv}} 
\def\p@enumiv{\p@enumiii\theenumiii}
\def\labelitemi{$\bullet$}
\def\labelitemii{\bf --}
\def\labelitemiii{$\ast$}
\def\labelitemiv{$\cdot$}
\def\verse{\let\\=\@centercr 
\list{}{\itemsep\z@ \itemindent -15pt\listparindent \itemindent 
\rightmargin\leftmargin\advance\leftmargin 15pt}\item[]}
\let\endverse\endlist
\def\quotation{\list{}{\listparindent 1.5em
\itemindent\listparindent
\rightmargin\leftmargin}\item[]}
\let\endquotation=\endlist
\def\quote{\list{}{\rightmargin\leftmargin}\item[]}
\let\endquote=\endlist
\def\descriptionlabel#1{\hfil \it #1}
\def\description{\list{}{\leftmargin\descriptionmargin
\labelwidth\leftmargin \advance\labelwidth -\labelsep 
\let\makelabel\descriptionlabel}}
\let\enddescription\endlist
\newdimen\descriptionmargin
\descriptionmargin=3em

\def\@begintheorem#1#2{\it \trivlist \item[\hskip \labelsep{\bf #1\ #2}]}
\def\@endtheorem{\endtrivlist}
\def\theequation{\arabic{equation}}
\arraycolsep 5pt \tabcolsep 6pt \arrayrulewidth .4pt \doublerulesep 2pt 
\tabbingsep \labelsep 
\skip\@mpfootins = \skip\footins
\fboxsep = 3pt \fboxrule = .4pt 

\def\footnoterule{\kern-1\p@ 
\hrule width .4\columnwidth 
\kern .6\p@} 
\long\def\@makefntext#1{\noindent \hangindent 5pt\hbox 
to 5pt{\hss $^{\@thefnmark}$}#1}

\c@topnumber=2
\def\topfraction{.7}
\c@bottomnumber=1
\def\bottomfraction{.3}
\c@totalnumber=3
\def\textfraction{.2}
\def\floatpagefraction{.5}
\c@dbltopnumber= 2
\def\dbltopfraction{.7}
\def\dblfloatpagefraction{.5}

\def\today{\ifcase\month\or
January\or February\or March\or April\or May\or June\or
July\or August\or September\or October\or November\or December\fi
\space\number\day, \number\year}

\smallskipamount=.5\parskip \medskipamount=\parskip
\bigskipamount=2\parskip
\ps@plain \pagenumbering{arabic} \onecolumn \@fileswfalse