Dear Francis,
these are the common issues that I mentioned in one of my previous
e-mails. TeX4ht doesn't support \mathbf{xxx}^x. Valid input is
{\mathbf{xxx}}^x. The {}_x issue is something different, this is really
known bug that I don't know how to fix.
Here are some other known issues: https://tug.org/tex4ht/doc/mml.html
Anyway, as these issues are really common and it isn't realistic to fix
them in already existing documents, here is a workaround. We can use Lua
script to preprocess the TeX file and fix these issues.
Here it is, filter.lua:
--------------
for line in io.lines() do
-- fix primes
line = line:gsub([[%'%^(.-)%_]], [[^{\prime %1}_]])
-- fix \mathrm{hello}^2
line = line:gsub([[(\[a-zA-Z]-)(%b{})([%^%_])]], [[{%1%2}%3]])
-- fix x_\mathrm{hello}
line = line:gsub([[([%_%^])(\[a-zA-Z]-)(%b{})]], "%1{%2%3}")
-- fix 10^2
line = line:gsub("([%d])([%_%^])", "{%1}%2")
-- fix {}_x
line = line:gsub("{}([%_%^])", "{\\HCode{}}%1")
print(line)
end
-------------
It can be executed in this way:
$ texlua filter.lua < MathML-bugs.tex | make4ht -f html5+mjcli -j MathML-bugs -
It seems to work on your sample. I plan to include support for TeX file
preprocessing in a future make4ht version. It should be easier to run
such code then.
Best regards,
Michal
Attached is a MWE illustrating the MathML generation errors that I
detected originally when using make4ht with mjcli. They appear to fall
into two classes: text in a different font with a super- or sub-script;
use of {} with a super- or sub-script. Please see also the comments at
the end of the attached file.
Francis
