Am 18.01.22 um 14:27 schrieb Joel via ntg-context:
One possible solution I see, since the textbooks and workbooks share the same macros, formatting, fonts, etc. is to just render them as a single file, resetting the page number at the start of each new book, then later use pdfjam to split the files, but I'm not sure how the index could tell readers which of the five "page 5's" (for example) the index is referring to. --Joel
In this case, you could use \part per workbook and use pageprefixsegments in \setupregister to add the part number in front of the page number. Otherwise, I guess it would be possible to read the .tuc files of the other products to create index entries. (Some Lua programming; shouldn’t bee too hard, but still way over my head.) Hraban