% The e-TRIP manual: How to validate e-TeX - last modified 05 Nov 1996
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\null
\vfill
\centerline{\titlefont A torture test for \eTeX}
\vskip 6pt
\centerline{({\sl Version 1, October 1996\/})}
\vskip 18pt
\centerline{by The \NTS\ Team}
\vskip 6pt
\centerline{Peter Breitenlohner, Max-Planck-Institut f\"ur Physik, M\"unchen}
\vskip 6pt
\centerline{Bernd Raichle, Institut f\"ur Informatik, Universit\"at Stuttgart}
\vfill
\centerline{\vbox{\hsize 4in
\noindent Programs that claim to be implementations of \eTeX\ are
supposed to be able to process the test routines described in this
report, producing the outputs described in this report.}}
\vskip 24pt
{\baselineskip 9pt
\eightrm\noindent
The preparation of this report was supported in part by DANTE,
Deutschsprachige Anwendervereinigung \TeX\ e.V.\hfil\break
`\TeX' is a trademark of the American Mathematical Society.

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\section Introduction.
The program \TeX82 by D.E.~Knuth is in the public domain, and its
algorithms are published; he has done this since he does not want to
discourage its use by placing proprietary restrictions on the software.
However, he doesn't want faulty imitations to masquerade as \TeX\
processors, since users want \TeX\ to produce identical results on
different machines.  He has copyrighted the programs so that he has some
chance to forbid unauthorized copies; he explicitly authorizes copying
of correct \TeX\ implementations, and not of incorrect ones!  In order
to determine, what is a correct implementation of \TeX, he has devised
a test suite for \TeX, the \.{TRIP} test [1].

The program \eTeX\ by `The \NTS\ Team' extends the capabilities of \TeX\
by adding a relatively small amount (less than 10 per cent) of code; it
is in the public domain, and its algorithms (beyond those of \TeX) are
published.  This report has been inspired by and is based on the
\.{TRIP} manual.  It describes the \.{e-TRIP} test, a test suite that
allows one to determine whether what one has is a correct implementation
of \eTeX.

If somebody claims to have a correct implementation of \eTeX, we will
not believe it until we see that the \.{e-TRIP} test is performed
properly.  We propose, in fact, that a program must meet two criteria
before it can justifiably be called \eTeX:  (1)~The person who wrote it
must be happy with the way it works at his or her installation; and
(2)~the program must produce the correct results from the \.{e-TRIP}
test.  Hence we are planning to do whatever we can to suppress any
systems that call themselves \eTeX\ without meeting conditions (1)
and~(2).  We have copyrighted the programs so that we have some chance
to forbid unauthorized copies; we explicitly authorize copying of
correct \eTeX\ implementations, and not of incorrect ones!

The process of generating an \eTeX\ implementation for a particular
system [2] is based on that of generating a \TeX\ implementation for the
same system.  Moreover, when \eTeX\ is used in compatibility mode, it is
supposed to be 100 per cent compatible with \TeX.  Thus a correct \eTeX\
implementation, when running in compatibility mode, must pass the
\.{TRIP} test.  In fact, the first part of the \.{e-TRIP} test for a
particular implementation of \eTeX\ consists in performing the standard
\.{TRIP} test (a)~for \eTeX\ in compatibility mode and (b)~for \eTeX\ in
extended mode.  The deviations in the test output from step~(a) should,
of course, be limited to those explicitly allowed by Knuth and described
in Appendix~A, item~5 of the \.{TRIP} manual.  Any additional deviations
in the test output from step~(b) must be accounted for by \eTeX's
additional algorithms and are described in detail in this report.  Once
an \eTeX\ implementation has passed these preliminary tests, it should be
subjected to the second part of the \.{e-TRIP} test.  There the extended
features and algorithms of \eTeX\ are tested under normal circumstances
as well as in situations a normal user would never dream of (in the
spirit of the \.{TRIP} test).

The remainder of this report consists of appendices, whose contents ought
to be described briefly here:

Appendix A explains in detail how to carry out the first part of the
test of \eTeX, given copies of the files described in the
\.{TRIP} manual.

Appendix B explains how to carry out the \eTeX\ specific test, given
copies of the files described in the other appendices.

Appendix C is \.{eTRIP.TEX}, a fiendish test file for \eTeX.

Appendix D is \.{eTRIP.PL}, the property-list description of a
special font called \.{etrip}.

Appendix E is \.{eTRIPIN.LOG}, a correct transcript file \.{eTRIP.LOG}
that results if \.{e-TRIPTEX} is applied to \.{eTRIP.TEX}.
This run of \.{e-TRIPTEX} also creates a binary format file called
\.{eTRIP.FMT} or similar.)

Appendix F is a correct transcript file \.{eTRIP.LOG} that results if
\.{e-TRIPTEX} or any other version of \eTeX\ is applied to \.{eTRIP.TEX}
with format \.{eTRIP.FMT}.

Appendix G is \.{eTRIP.FOT}, an abbreviated version of Appendix F that
appears on the user's terminal during the run that produces
\.{eTRIP.LOG}.

\vskip 24pt plus 24pt
\section References.
\item {[1]}
{\sl A torture test for \TeX\/},
by Donald E.~Knuth, Stanford Computer Science Report~1027.

\item {[2]}
{\sl How to generate \eTeX\/},
by The \NTS\ Team (Peter Breitenlohner and Phil Taylor).

\item {[3]}
{\sl The \.{WEB} system of structured documentation\/},
by Donald E.~Knuth, Stanford Computer Science Report~980.

\item {[4]}
{\sl \TeX ware\/}, by Donald E.~Knuth and David R.~Fuchs,
Stanford Computer Science Report~1097.

\vfill\eject

\section Appendix A: How to test \eTeX\ (part 1).

\item{0.} Let's assume that you have copies of the files \.{TRIP.TEX},
\.{TRIP.PL}, \.{TRIPIN.LOG}, \.{TRIP.LOG}, \.{TRIP.TYP}, and
\.{TRIP.FOT} as described in Appendices~B, C, D, E, F, and~G of the
\.{TRIP} manual [1] (in a safe place so that these ``master'' files will
not be clobbered).  Furthermore, let's suppose that you have a working
\.{WEB} system [3], and that you have working programs \.{PLtoTF} and
\.{DVItype}, as described in the \TeX ware report [4].  Finally let's
assume that you are able to generate \eTeX\ as described in [2].

\item{1.} Use \.{PLtoTF} to convert \.{TRIP.PL} into \.{TRIP.TFM};
install \.{TRIP.TFM} in the standard file area for \TeX\ font metric
files (or set a suitable environment variable or similar such that these
files will be found by the program).

\item{2.} Generate \.{e-TRIPTEX}, a special version of \.{e-INITEX}.
The parameters for \.{e-TRIPTEX} should agree with those for \.{TRIPTEX}
(as described in [1]), except that you should set \\{pool\_size} to a
value $\ge32000$ and \\{max\_strings} to a value $\ge3200$.

\item{3.} Perform the \.{TRIP} test as described in Appendix~A,
items~3--7 of [1], with \.{e-TRIPTEX} as prepared in step~2.  The program
will run in compatibility mode and should therefore be fully compatible
with \.{TRIPTEX} as described in [1]; apart from the allowed differences
listed in item~5, the test output should deviate from the master files in
the following two \eTeX-specific points (and only in these):

\itemitem{a)} The name and version by which the program announces itself
will be different; the extension of the format file produced during the
first \.{e-TRIPTEX} run may be different.

\itemitem{b)} The message `\.{entering compatibility mode}' will appear
on the terminal and in the \.{TRIP.LOG} files.

\item{4.} Perform steps 3--7 of the \.{TRIP} test once again with
\.{e-TRIPTEX}.  During the first run type `\.{*\char`\\input trip}'
instead of `\.{\char`\\input trip}'.  As a consequence \.{e-TRIPTEX}
will run in extended mode and the test output should differ from that
of step~3 above in the following respects (and only in these):

\itemitem{a)} The date and\slash or time will naturally be different.

\itemitem{b)} The input `\.{*\char`\\input trip}' instead of
`\.{\char`\\input trip}' is recorded in the first \.{TRIP.LOG} file; the
word `\.{compatibility}' is replaced by `\.{extended}'.

\itemitem{c)} If the date has changed, the number of string characters
dumped by the first \.{e-TRIPTEX} run may vary by $\pm2$.

\itemitem{d)} Both \.{e-TRIPTEX} runs report \extracs~additional
multiletter control sequences (in the \.{TRIP.LOG} files).

\itemitem{e)} The second \.{e-TRIPTEX} run reports different memory
usage statistics during the output of pages; there will be the three
(non consecutive) lines\verblines 3
Memory usage before: 151&313; after: 102&278; still untouched: 1613
Memory usage before: 851&436; after: 290&417; still untouched: 175
Memory usage before: 330&428; after: 292&415; still untouched: 175
instead of\verblines 3
Memory usage before: 159&313; after: 102&278; still untouched: 1613
Memory usage before: 895&436; after: 290&417; still untouched: 175
Memory usage before: 334&428; after: 292&415; still untouched: 175
The first and third of these appear on the terminal and in the
\.{TRIP.LOG} file, the second one in \.{TRIP.LOG} only.  Next the second
run reports the unfinished group(s) when the program terminates; there
are three additional lines (the first of them blank) on the terminal and
in the \.{TRIP.LOG} file\verblines 3

### 1: semi simple group entered at line 429 (begingroup)
### 0: bottom level
The second \.{TRIP.LOG} contains six additional lines\verblines 1
{restoring \predisplaydirection=0}
and ten lines displaying an \.{\char`\\hbox} contain the additional text
`\.{, display}'.
Finally the second \.{TRIP.LOG} reports the use of \extrasv~additional
save (\.{s}) stack positions.

\vfill\eject

\section Appendix B: How to test \eTeX\ (part 2).

\item{5.} Assume that you have copies of the ``master'' files
\.{eTRIP.TEX}, \.{eTRIP.PL}, \.{eTRIPIN.LOG}, \.{eTRIP.LOG}, and
\.{eTRIP.FOT}, as in Appendices C, D, E, F, and~G (again in a safe
place).

\item{6.} Use \.{PLtoTF} to convert \.{eTRIP.PL} into \.{eTRIP.TFM};
install \.{eTRIP.TFM} in the standard file area for \TeX\ font metric
files (or set a suitable environment variable or similar).

\item{7.} Run \.{e-TRIPTEX}; in response to the `\.{**}' prompt, type
`\.{*etrip}'.  You should get an output file \.{eTRIP.LOG} that matches
the file \.{eTRIPIN.LOG} (Appendix~E).  Contrary to the analogous step
in the \.{TRIP} test (steps~3 and~4 above) there should be no error
messages; lines in the output saying ``Emergency stop'' would indicate
that you have performed this test with a standard \TeX\ or with \eTeX\
in compatibility mode.

\item{8.} Run \.{e-TRIPTEX} again; this time type
`\.{\&etrip{\char'40}etrip}'.  You should get an output \.{eTRIP.LOG}.
Furthermore, your terminal should receive output that matches
\.{eTRIP.FOT} (Appendix~G).  Once again, the terminal will be getting no
output during the middle part of this test.

\item{9.} Compare the \.{eTRIP.LOG} file from step 8 with the ``master''
\.{eTRIP.LOG} file of step~5.  There should be no lines saying
``Emergency stop'' (see above) or ``Bug in your e-TeX implementation'';
there should be perfect agreement between these files except in the
following respects:

\itemitem{a)} The dates and possibly the file names will naturally be
different.

\itemitem{b)} Glue settings in the displays of \TeX\ boxes are subject
to system-dependent rounding, so slight deviations are permissible.
However, such deviations apply only to the `\.{glue set}' values that
appear at the end of an \.{\char'134hbox} or \.{\char'134vbox} line; all
other numbers should agree exactly, since they are computed with integer
arithmetic in a prescribed system-independent manner.

\itemitem{c)} The amount of space in kerns that are marked ``for
accent'' are, similarly, subject to system-dependent rounding.

\itemitem{d)} If you had different values for \\{stack\_size},
\\{buf\_size}, etc., the corresponding capacity values will be different
when they are printed out at the end.

\itemitem{e)} Help messages may be different; indeed, the author of
\TeX\ encourages non-English help messages in versions of \TeX\ for
people who don't understand English as well as some other language.
Similarly, \eTeX\ could well be used with non-English help messages.

\itemitem{f)} The total number and length of strings at the end may well
be different.

\itemitem{g)} If your \eTeX\ uses a different memory allocation or
packing scheme or \.{DVI} output logic, the memory usage statistics may
change.

\vfill\eject

\section Appendix C: The \.{eTRIP.TEX} file.
The contents of the test routine are prefixed here with line numbers,
for ease in comparing this file with the error messages printed later;
the line numbers aren't actually present.
\runninghead{APPENDIX C: \.{eTRIP.TEX} (CONTINUED)}

\vskip 8pt
\begingroup\count255=0
\everypar{\global\advance\count255 by 1
  \hbox to 20pt{\sevenrm\hfil\the\count255\ \ }}
\verbatim{etrip.tex}
\endgroup
\vfill\eject

\section Appendix D: The \.{eTRIP.PL} file.
At the moment the \.{eTRIP.PL} file is just a copy of \.{TRIP.PL} as
described in Appendix~C of [1].

\section Appendix E: The \.{eTRIPIN.LOG} file.
When \.{e-TRIPTEX} makes the \.{eTRIP.FMT} file, it also creates a file
called \.{eTRIP.LOG} that looks like this.
\runninghead{APPENDIX E: \.{eTRIPIN.LOG} (CONTINUED)}

\vskip8pt
\verbatim{etripin.log}
\vfill\eject

\section Appendix F: The \.{eTRIP.LOG} file.
Here is the major output of the \.{e-TRIP} test; it is generated by
running \.{e-TRIPTEX} and loading \.{eTRIP.FMT}, then reading
\.{eTRIP.TEX}.
\runninghead{APPENDIX F: \.{eTRIP.LOG} (CONTINUED)}

{\let\tt=\eighttt\leftskip 1in\baselineskip 9pt plus .1pt minus .1pt
\vskip8pt
\verbatim{etrip.log}
}
\vfill\eject

\section Appendix G: The \.{eTRIP.FOT} file.
This shows what appeared on the terminal while Appendix F was being
produced.
\runninghead{APPENDIX G: \.{eTRIP.FOT} (CONTINUED)}

\vskip8pt
\verbatim{etrip.fot}

\vfill\end