%% LaTeX2e file `t.tex'
%%
\hsize 3in
\baselineskip 13pt
\pdfoutput=1              % we will produce PDF instead of DVI
\pdfannottext
    open                  % optional specification if the text annotation is implicitly opened
    {The text annotation} % the text itself
\def\BL{\pdfannotlink
    depth 3pt height 8pt  % optional specification for link size
    1                     % key of destination
    border 0 0 1          % optional specification for link border
}
\def\EL{\pdfendlink}
\pdfoutline
    1                     % key of destination
    0                     % number of sub-entries of this item
    {The outline entry}   % Text of this item
\pdfdestxyz
    1                     % key of this destination
    zoom 2                % optional zoom factor
%\pdfdestfit  1 or %\pdfdestfith 1 or %\pdfdestfitv 1
%\pdfdestfitr 1 ... \pdfendfitr

This is \TeX, a document compiler intended to produce typesetting of
high quality.  The PASCAL program that follows is the definition of
\TeX82, a standard version of \TeX\ that is designed to be highly
portable so that identical output will be obtainable on a great
variety of computers.

The main purpose of the following program is to explain the algorithms
of \TeX\ as clearly as possible. \BL As a result, the program will not
necessarily be very efficient when a particular PASCAL compiler has
translated it into a particular machine language.\EL\ However, the
program has been written so that it can be tuned to run efficiently in
a wide variety of operating environments by making comparatively few
changes. Such flexibility is possible because the documentation that
follows is written in the WEB language, which is at a higher level
than PASCAL; the preprocessing step that converts WEB to PASCAL is
able to introduce most of the necessary refinements.  Semi-automatic
translation to other languages is also feasible, because the program
below does not make extensive use of features that are peculiar to
PASCAL.

A large piece of software like \TeX\ has inherent complexity that cannot
be reduced below a certain level of difficulty, although each individual
part is fairly simple by itself. The WEB language is intended to make
the algorithms as readable as possible, by reflecting the way the
individual program pieces fit together and by providing the
cross-references that connect different parts. Detailed comments about
what is going on, and about why things were done in certain ways, have
been liberally sprinkled throughout the program.  These comments explain
features of the implementation, but they rarely attempt to explain the
\TeX\ language itself, since the reader is supposed to be familiar with
{\sl The \TeX book}.
\bye