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> There are also essentially no total languages today.

As you obviously meant, no total general-purpose languages. I'm sure that HTML is total, for example. You also later qualified that "no total languages" meant "no widespread, simple, total languages", which I think is a very different statement!



HTML has no reduction/evaluation rules and so it can't have a semantics in the same way as real programming languages. You could think of a "layout semantics" relating HTML and a given environment (screen size, fonts, etc.) to the resulting box model or rendered page, but that's not very interesting from the standpoint of totality: we already know that Web browsers are supposed to show something no matter how mangled their input is.


> HTML has no reduction/evaluation rules and so it can't have a semantics in the same way as real programming languages.

It seems to me that your next sentence addresses this better than I could.

> that's not very interesting from the standpoint of totality: we already know that Web browsers are supposed to show something no matter how mangled their input is.

So isn't it interesting that they do that? I think that the prevalence of scripting languages on the modern web (and, if you like to look farther back in history, the reluctant Turing completeness of TeX) strongly suggests that it wasn't at all inevitable that we would get a total language for web design.

That is, to prove that it is total is presumably not much of an accomplishment, but that it is total is very interesting (and, from the point of view of the success of the web, important) indeed.


Yes, there's also the subset of SQL that is total - or, at least, not-Turing-complete.

Edit: As far as HTML goes, I was attempting to describe "programming languages" - or perhaps algorithmic languages - which I don't consider HTML falling under.


Is that not true of every not-total/turing-complete language?




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