# long equation do not show up using $..$ but shows up using \begin{align*}…\end{align*}

I have a long equation, which is 32,497 characters long generated from a computer algebra system.

When I write it as

$equation here$


and compile the latex file using lualatex, the pdf does not contain the equation. the space where it is supposed to be is all blank.

When I do the same thing using

\begin{align*}
equation here
\end{align*}


Then it shows up (the first part of it, as the rest goes off the page).

The question is: why does the equation not show up using $..$?

Since the equation is very long, I tried to post it here but found it will be very hard to copy the MWE which contains it. So I put the MWE plain latex file on my web page here long_equation.tex

The PDF file is long_equation.pdf and the log file is long_equation.log

The MWE looks like the following (without the actual equation in it, since it is too long)

\documentclass[12pt]{article}
\usepackage{amsmath}
\DeclareMathOperator{\WhittakerM}{WhittakerM}
\begin{document}

The equation is

$long equation here$

Did you see it?

The equation is

\begin{align*}
same long equation here
\end{align*}

Did you see it?

\end{document}


compiling the above using lualatex long_equation.tex gives this output

Here is the output on the screen when compiling the file with only $...$  in it

>lualatex long_equation.tex
This is LuaTeX, Version 1.07.0 (TeX Live 2018)
restricted system commands enabled.
(./long_equation.tex
LaTeX2e <2018-04-01> patch level 5

luaotfload | main : initialization completed in 0.157 seconds
(/usr/local/texlive/2018/texmf-dist/tex/latex/base/article.cls
Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
(/usr/local/texlive/2018/texmf-dist/tex/latex/base/size12.clo))
(/usr/local/texlive/2018/texmf-dist/tex/latex/amsmath/amsmath.sty
For additional information on amsmath, use the ?' option.
(/usr/local/texlive/2018/texmf-dist/tex/latex/amsmath/amstext.sty
(/usr/local/texlive/2018/texmf-dist/tex/latex/amsmath/amsgen.sty))
(/usr/local/texlive/2018/texmf-dist/tex/latex/amsmath/amsbsy.sty)
(/usr/local/texlive/2018/texmf-dist/tex/latex/amsmath/amsopn.sty))
(./long_equation.aux) [1{/usr/local/texlive/2018/texmf-var/fonts/map/pdftex/upd
map/pdftex.map}] (./long_equation.aux))
457 words of node memory still in use:
5 hlist, 2 vlist, 2 rule, 2 glue, 4 kern, 1 glyph, 7 attribute, 48 glue_spec
, 7 attribute_list, 1 write nodes
avail lists: 1:2,2:8427,3:15206,4:322,5:1711,6:3,7:17655,8:12931,9:6966,11:1

</usr/local/texlive/2018/texmf-dist/fonts/opentype/public/lm/lmroman12-regular.
otf></usr/local/texlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmex10.p
fb></usr/local/texlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmmi12.pf
b></usr/local/texlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmmi6.pfb>
</usr/local/texlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmmi8.pfb></
usr/local/texlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></us
r/local/texlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/l
ocal/texlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmr8.pfb></usr/loca
l/texlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmsy10.pfb></usr/local
/texlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmsy8.pfb></usr/local/t
exlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmti12.pfb>
Output written on long_equation.pdf (1 page, 157834 bytes).
Transcript written on long_equation.log.
>


Here is the log file

>cat long_equation.log
This is LuaTeX, Version 1.07.0 (TeX Live 2018)  (format=lualatex 2018.12.4)  7 JAN 2019 11:58
restricted system commands enabled.
**long_equation.tex
(./long_equation.tex
LaTeX2e <2018-04-01> patch level 5
n
Lua module: lualibs 2018-10-18 2.61 ConTeXt Lua standard libraries.
Lua module: lualibs-extended 2018-10-18 2.61 ConTeXt Lua libraries -- extended c
ollection.
luaotfload | conf : Root cache directory is /home/me/.texlive2018/texmf-var/luat
ex-cache/generic/names.
Inserting luaotfload.node_processor' at position 1 in pre_linebreak_filter'.
Inserting luaotfload.node_processor' at position 1 in hpack_filter'.
andling
Inserting luaotfload.define_font' at position 1 in define_font'.
s
luaotfload | conf : Root cache directory is /home/me/.texlive2018/texmf-var/luat
ex-cache/generic/names.
y functions
Inserting luaotfload.aux.set_sscale_dimens' at position 1 in luaotfload.patch_
font'.
Inserting luaotfload.aux.patch_cambria_domh' at position 2 in luaotfload.patch
_font'.
Inserting luaotfload.aux.fixup_fontdata' at position 1 in luaotfload.patch_fon
t_unsafe'.
Inserting luaotfload.aux.set_capheight' at position 3 in luaotfload.patch_font
'.
Inserting luaotfload.rewrite_fontname' at position 4 in luaotfload.patch_font'
.
luaotfload | main : initialization completed in 0.159 seconds
(/usr/local/texlive/2018/texmf-dist/tex/latex/base/article.cls
Document Class: article 2014/09/29 v1.4h Standard LaTeX document class
(/usr/local/texlive/2018/texmf-dist/tex/latex/base/size12.clo
File: size12.clo 2014/09/29 v1.4h Standard LaTeX file (size option)
\c@part=\count80
\c@section=\count81
\c@subsection=\count82
\c@subsubsection=\count83
\c@paragraph=\count84
\c@subparagraph=\count85
\c@figure=\count86
\c@table=\count87
\abovecaptionskip=\skip41
\belowcaptionskip=\skip42
\bibindent=\dimen102
)
(/usr/local/texlive/2018/texmf-dist/tex/latex/amsmath/amsmath.sty
Package: amsmath 2017/09/02 v2.17a AMS math features
\@mathmargin=\skip43

For additional information on amsmath, use the ?' option.
(/usr/local/texlive/2018/texmf-dist/tex/latex/amsmath/amstext.sty
Package: amstext 2000/06/29 v2.01 AMS text

(/usr/local/texlive/2018/texmf-dist/tex/latex/amsmath/amsgen.sty
File: amsgen.sty 1999/11/30 v2.0 generic functions
\@emptytoks=\toks14
\ex@=\dimen103
))
(/usr/local/texlive/2018/texmf-dist/tex/latex/amsmath/amsbsy.sty
Package: amsbsy 1999/11/29 v1.2d Bold Symbols
\pmbraise@=\dimen104
)
(/usr/local/texlive/2018/texmf-dist/tex/latex/amsmath/amsopn.sty
Package: amsopn 2016/03/08 v2.02 operator names
)
LaTeX Info: Redefining \frac on input line 213.
\uproot@=\count89
\leftroot@=\count90
LaTeX Info: Redefining \overline on input line 375.
\classnum@=\count91
\DOTSCASE@=\count92
LaTeX Info: Redefining \ldots on input line 472.
LaTeX Info: Redefining \dots on input line 475.
LaTeX Info: Redefining \cdots on input line 596.
\Mathstrutbox@=\box26
\strutbox@=\box27
\big@size=\dimen105
LaTeX Font Info:    Redeclaring font encoding OML on input line 712.
LaTeX Font Info:    Redeclaring font encoding OMS on input line 713.
\macc@depth=\count93
\c@MaxMatrixCols=\count94
\dotsspace@=\muskip10
\c@parentequation=\count95
\dspbrk@lvl=\count96
\tag@help=\toks15
\row@=\count97
\column@=\count98
\maxfields@=\count99
\andhelp@=\toks16
\eqnshift@=\dimen106
\alignsep@=\dimen107
\tagshift@=\dimen108
\tagwidth@=\dimen109
\totwidth@=\dimen110
\lineht@=\dimen111
\@envbody=\toks17
\multlinegap=\skip44
\multlinetaggap=\skip45
\mathdisplay@stack=\toks18
LaTeX Info: Redefining $on input line 2817. LaTeX Info: Redefining$ on input line 2818.
)
(./long_equation.aux)
\openout1 = long_equation.aux

LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 6.
LaTeX Font Info:    ... okay on input line 6.
LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 6.
LaTeX Font Info:    ... okay on input line 6.
LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 6.
LaTeX Font Info:    ... okay on input line 6.
LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 6.
LaTeX Font Info:    ... okay on input line 6.
LaTeX Font Info:    Checking defaults for TU/lmr/m/n on input line 6.
LaTeX Font Info:    ... okay on input line 6.
LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 6.
LaTeX Font Info:    ... okay on input line 6.
LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 6.
LaTeX Font Info:    ... okay on input line 6.
[1

{/usr/local/texlive/2018/texmf-var/fonts/map/pdftex/updmap/pdftex.map}] (./long
_equation.aux))

Here is how much of LuaTeX's memory you used:
889 strings out of 494407
381512,89155 words of node,token memory allocated
457 words of node memory still in use:
5 hlist, 2 vlist, 2 rule, 2 glue, 4 kern, 1 glyph, 7 attribute, 48 glue_spec,
7 attribute_list, 1 write nodes
avail lists: 1:2,2:8427,3:15206,4:322,5:1711,6:3,7:17655,8:12931,9:6966,11:1
5106 multiletter control sequences out of 65536+600000
32 fonts using 1918303 bytes
27i,8n,20p,32516b,125s stack positions out of 5000i,500n,10000p,90000000b,100000s
</usr/local/texlive/2018/texmf-dist/fonts/opentype/public/lm/lmroman12-regular.o
tf></usr/local/texlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmex10.pfb
></usr/local/texlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmmi12.pfb><
/usr/local/texlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmmi6.pfb></us
r/local/texlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmmi8.pfb></usr/l
ocal/texlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmr12.pfb></usr/loca
l/texlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmr6.pfb></usr/local/te
xlive/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmr8.pfb></usr/local/texliv
e/2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmsy10.pfb></usr/local/texlive/
2018/texmf-dist/fonts/type1/public/amsfonts/cm/cmsy8.pfb></usr/local/texlive/201
8/texmf-dist/fonts/type1/public/amsfonts/cm/cmti12.pfb>
Output written on long_equation.pdf (1 page, 157834 bytes).

PDF statistics: 55 PDF objects out of 1000 (max. 8388607)
38 compressed objects within 1 object stream
0 named destinations out of 1000 (max. 131072)
1 words of extra memory for PDF output out of 10000 (max. 100000000)

>


TL 2018 on Linux.

• ...anything in the .log? – Werner Jan 7 at 17:46
• @Werner I put the log file in the question. Thanks. – Nasser Jan 7 at 17:52
• I think the equation might be so wide it causes an integer overflow. – Circumscribe Jan 7 at 17:53
• @Nasser: I think it still overflows, but that the effect is different because align works differently. (Normally aligned equations that are too wide start at the leftmost edge of the text area; this one starts at the centre.) – Circumscribe Jan 7 at 18:01
• This produces the entire equation on a single line, in case you need it :). A few other font parameters may need some tweaking. – Circumscribe Jan 7 at 20:07

The formula is built and boxed. However, it exceeds the maximum width by a very large amount and, due to how binary arithmetic works, its width is advertised as -4919.6661pt, whose numeric value is -322415238.

Thus the box is typeset, but nothing can be seen because it is outside the margin of the page.

If you try

$\hspace{4919.6661pt}<monster>$


you can see the end of the formula.

Why does align show at least some part of the formula? Because it internally uses \halign and not display math mode.

Maybe this could be managed in a different way, but I don't think that it's something to worry about: six meter long formulas are nothing anybody would like to see.

• You are wrong..... I would like to see a six meter long equation. – hpekristiansen Jan 7 at 19:47
• Brave guy to state You are wrong to egreg.... lol – Sigur Jan 7 at 20:02

You can make equation look like align but in either case it prints the expression on one line so 99% of it off the page. If you really must print such an expression you need to take more drastic actions to keep it visible. This is visible but of course completely unreadably ugly.

\documentclass[12pt]{article}

\usepackage{amsmath}
\def\WhittakerM{\textrm{WhittakerM}}

\begin{document}

The equation is
\begin{center}
\itshape\footnotesize
\catcode\^=13
\def^#1{\textsuperscript{(\tiny#1)}}
\def\left{\penalty0 }
\def\right{\penalty0 }
\def\frac#1#2{(#1)
/\penalty0(#2)
\penalty0 }
w
\left( x,y \right)
={\it \_F1}
\left( {\frac {1}{{b}^{2}
\left(......
\end{center}

Did you see it?

\end{document}
`