[tex4ht] [bug #481] Problem with Braces / Brackets in Maths equations using mk4ht latex->mathml

[Nasser M. Abbasi]

On 8/21/2020 3:54 AM, Michal Hoftich wrote:
> Hi Nasser,
> 
>> After changing the command and adding "mathml", now some
>> of my latex files no longer compile.
>>
>> Please see this MWE
>>
>> \documentclass{article}
>> \usepackage{amsmath}
>> \begin{document}
>> $n^\text{th}$
>> \end{document}
>>
>> THe above used to compile OK using
>>
>>          make4ht filename.tex "mathjax,htm"
>>
>> But now using
>>
>>          make4ht filename.tex "mathml,mathjax,htm"
>>
>> it gives error
> 

> I can confirm this issue. BTW, you will get this error even without the
> "mathml" option. It is a know issue, see:
> 
> https://tug.org/tex4ht/doc/mml.html
> 

Hello Michal,

FYI.

I found another example where it gives error with mathml. This below
makes smiley face using latex:

\documentclass[12pt]{article}
\usepackage{amsmath}
\begin{document}
$\widehat{\dbinom{\odot_\text{v}\odot}{\wr}}$
\end{document}

The above compiles with no error using

      make4ht -ulm default -a debug foo3.tex "htm"

But using

     make4ht -ulm default -a debug foo3.tex "mathml,htm"

....
r/local/texlive/2020/texmf-dist/tex/generic/tex4ht/html-mml.4ht) (/usr/local/texlive/2020/texmf-dist/tex/generic/tex4ht/html5.4ht)) (/usr/local/texlive/2020/texmf-dist/tex/latex/l3backend/l3backend-dvips.def) (./foo3.aux) (/usr/local/texlive/2020/texmf-dist/tex/latex/base/ts1cmr.fd)
! Argument of \n:text@: has an extra }.
<inserted text>
\par
l.4 $\widehat{\dbinom{\odot_\text{v}\odot}{\wr}}
                                               $
?


May be the latex code here is also not valid?. I did not write the above
latex code myself. I found it long time ago on the net. Do not remember now
from where.

Best
--Nasser