This modification of the macro chapter-numbered-title, which you can put
in the preamble of your document (Paste from -> TeXmacs), seems to do
what you want

<assign|chapter-numbered-title|<macro|title|<chapter-title|<the-chapter>.
<chapter-text><vspace|1fn><new-line><arg|title>>>>

I am not yet convinced that the modification is all that you need to do
because there might be some additional change for the table of contents
and for the header. The definition of the macro chapter is

<assign|chapter|<macro|title|<assign|chapter-numbered|<compound|chapter-display-numbers>><assign|chapter-prefix|<macro|<compound|the-chapter>.>><compound|next-chapter><compound|chapter-clean><compound|chapter-header|<arg|title>><compound|chapter-toc|<arg|title>><if|<value|chapter-numbered>|<compound|chapter-numbered-title|<arg|title>>|<compound|chapter-unnumbered-title|<arg|title>>>>>

and if you notice some other things that should be changed that is the
macro where I would start investigating.

This blog post shows how to use the macro editor which gives quick
access to the macro definitions:
https://texmacs.gitee.io/notes/docs/macro-editor.html

On the other hand the online manual
https://www.texmacs.org/tmweb/manual/webman-style.en.html seemed to me
outdated (searching with the macro editor I did not find the
sectional-normal macro, which is cited in the manual page, in the
definition of the section macro) but I read it only very quickly.

G.



On 23.09.22 11:31, Kovács Zoltán wrote:
> After fixing the copy/paste issue, I have some further questions. :-)
> I chose the book document class, but in my language, instead of seeing
> Part I or Chapter 1, I should reverse these words and put a point
> after the number:
> "I. rész", "1. fejezet". (I guess it is very similar in the Basque
> language,
> however, it is not yet supported in TeXmacs.)
> Is there a way to fix this?
> (LaTeX handles this well. Also, LyX handles the order quite well for
> some document classes, but not always.)
> Thanks in advance.
> Best, Zoltán
>
> --
>
> *Dr. Zoltán** Kovács, MSc*
>
> Institut Ausbildung
>
> /Private Pädagogische Hochschule der Diözese Linz
> //Private University of Education, Diocese Linz
> //Salesianumweg 3, 4020 Linz//
> //Mail: address@hidden/
>
> /Web: www.ph-linz.at <http://www.ph-linz.at/>/
>
> /
> /
>