This is pdfTeX, Version 3.14159265-2.6-1.40.20 (TeX Live 2019/W32TeX) (preloaded format=pdflatex 2020.2.7)  8 FEB 2020 19:55
entering extended mode
 restricted \write18 enabled.
 %&-line parsing enabled.
**document.tex
(./document.tex
LaTeX2e <2020-02-02>
L3 programming layer <2020-02-03>
(c:/texlive/2019/texmf-dist/tex/latex/base/article.cls
Document Class: article 2019/12/20 v1.4l Standard LaTeX document class
(c:/texlive/2019/texmf-dist/tex/latex/base/size10.clo
File: size10.clo 2019/12/20 v1.4l Standard LaTeX file (size option)
)
\c@part=\count167
\c@section=\count168
\c@subsection=\count169
\c@subsubsection=\count170
\c@paragraph=\count171
\c@subparagraph=\count172
\c@figure=\count173
\c@table=\count174
\abovecaptionskip=\skip47
\belowcaptionskip=\skip48
\bibindent=\dimen134
)
(c:/texlive/2019/texmf-dist/tex/latex/l3backend/l3backend-pdfmode.def
! Undefined control sequence.
\periodx ->\ifcat \space \next 
                               \next \expandafter \uppercasesingleletter \el...
l.29   {L3 backend support: PDF mode}
                                     
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

! Undefined control sequence.
\periodx ->\ifcat \space \next \next 
                                     \expandafter \uppercasesingleletter \el...
l.29   {L3 backend support: PDF mode}
                                     
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

! Undefined control sequence.
<recently read> \next 
                      
l.29   {L3 backend support: PDF mode}
                                     
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

! Undefined control sequence.
.->\period \afterassignment \periodx \let \next 
                                                = 
l.29   {L3 backend support: PDF mode}
                                     
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.

File: l3backend-pdfmode\period \afterassignment \let = def 2020-02-03 L3 backen
d support: PDF mode
! Missing \endcsname inserted.
<to be read again> 
                   \period 
l.29   {L3 backend support: PDF mode}
                                     
The control sequence marked <to be read again> should
not appear between \csname and \endcsname.

\l__kernel_color_stack_int=\count175
\l__pdf_internal_box=\box45
) (./document.aux)
\openout1 = `document.aux'.

LaTeX Font Info:    Checking defaults for OML/cmm/m/it on input line 7.
LaTeX Font Info:    ... okay on input line 7.
LaTeX Font Info:    Checking defaults for OMS/cmsy/m/n on input line 7.
LaTeX Font Info:    ... okay on input line 7.
LaTeX Font Info:    Checking defaults for OT1/cmr/m/n on input line 7.
LaTeX Font Info:    ... okay on input line 7.
LaTeX Font Info:    Checking defaults for T1/cmr/m/n on input line 7.
LaTeX Font Info:    ... okay on input line 7.
LaTeX Font Info:    Checking defaults for TS1/cmr/m/n on input line 7.
LaTeX Font Info:    ... okay on input line 7.
LaTeX Font Info:    Checking defaults for OMX/cmex/m/n on input line 7.
LaTeX Font Info:    ... okay on input line 7.
LaTeX Font Info:    Checking defaults for U/cmr/m/n on input line 7.
LaTeX Font Info:    ... okay on input line 7.

! Missing \endcsname inserted.
<to be read again> 
                   \period 
l.7 \begin{document}
                    
The control sequence marked <to be read again> should
not appear between \csname and \endcsname.

[1

{c:/texlive/2019/texmf-var/fonts/map/pdftex/updmap/pdftex.map}]
(./document.aux) ) 
Here is how much of TeX's memory you used:
 366 strings out of 481248
 6221 string characters out of 5922089
 236107 words of memory out of 5000000
 15708 multiletter control sequences out of 15000+600000
 532338 words of font info for 24 fonts, out of 8000000 for 9000
 1141 hyphenation exceptions out of 8191
 25i,4n,19p,139b,97s stack positions out of 5000i,500n,10000p,200000b,80000s
<c:/texlive/2019/texmf-dist/fonts/type1/public/amsfonts/cm/cm
r10.pfb>
Output written on document.pdf (1 page, 12013 bytes).
PDF statistics:
 12 PDF objects out of 1000 (max. 8388607)
 7 compressed objects within 1 object stream
 0 named destinations out of 1000 (max. 500000)
 1 words of extra memory for PDF output out of 10000 (max. 10000000)