Am 04.01.2021 um 15:30 schrieb Hans Hagen
: On 1/4/2021 2:18 PM, Ulrike Fischer wrote:
Of course it helps to understand basic TeX stuff – but you’re not supposed to use (plain) TeX commands in LaTeX, while it is or was much more usual in ConTeXt. Well we discourage the use of plain commands to avoid that new users trip over bewildering errors from stuff like "abc \hskip 2cm plus cde", but it is not forbidden to use them. Hm, \hskip is not a plain command but a language primitive. And there's nothing wrong with using primitives, assuming that one knows how they work (and in this case that a \relax does wonders).
One of those 'persistent' wrong ideas about context is that it somehow is kind of plain but decided to not waste time arguing that. There are actually not that many commands in 'plain' anyway. Much of plain tex is setting up math (and all macro packages support those symbolic names and the basic math structures), some fonts (all macro package set up some font system and maybe some aliases that make it easier for plain users), but as soon as one uses latex or context or ... some different output routine kicks in, table mechanisms show up, \item has a different meaning, etc. (The early macro packages were kind of plain themselves: demanding redefinition of internals and such.)
I don’t know anything about Knuth’s Plain TeX, I always mean plain TeX. ;) And I mix up primitives and "basic" commands, because it doesn’t matter for me. My mistake. What I meant: In ConTeXt code (by users and maybe only in old sources) I see a lot of TeX constructs, e.g. you’re using \def (TeX) and not \define (ConTeXt) because you know it makes no difference. And when I can’t achieve the right vertical spacing with \blank[something], I use \vskip, because it works. LaTeX replaces many basic commands/primitives (\vskip -> \vspace), ConTeXt might too, but with the same name. Hraban