> There is a section "Digits into Numbers"
> in tex4ht-xhtmml-xtpipes.tex file.
> If I read it correctly, the code deals with
> merging "mn" nodes. Apparently Eitan's approach
> was to postprocess html file with xtpipes (and not to fix c-code).
that's great observation! I can see that this file tries to solve more
issues, like child <mi> elements in <mstyle> or some common HTML issues.
It can be requested using -cxhtmml option for t4ht, like:
make4ht -u filename.tex "mathml" "" "-cxhtmml"
I can see some issues here though: it translates utf8 characters to HTML
entites and it insert end tags for <meta> or <link> elements, which
results in non-valid HTML file.
Anyway, I think I will make a default filter to fix these issues for
make4ht, as Eitan clearly used a post-processing himself.