Re: [dvd-discuss] Fwd: Australian Court rules: Films aren't software

["Robert S. Thau" <rst(at)ai.mit.edu>]

Peter D. Junger writes:
 > "Robert S. Thau" writes:
 > : (The flip side of the argument is that if you call Postscript
 > : documents "programs", then you can also call plain text documents
 > : "programs" in a language in which each character is a "command" whose
 > : semantics are to print that character and advance one space, with a
 > : few extras for newline, etc.  But it is possible to draw principled
 > : distinctions here; for instance Postscript is Turing-complete, if run
 > : on a machine with space for an infinite stack, and the "ASCII command
 > : set" is not...).
 > 
 > Turing completeness does not support a principled distinction.  
 > The PostScript language program may be Turing-complete, but few
 > if any PostScript programs are Turing complete.

I'd wager most programs in *any* practical language aren't
Turing-complete, in the sense that (with suitable inputs and backing
storage) they can be made to perform any desired computation.

But we can make a principled distinction between a document that is
*written in* a Turing-complete machine-executable language, such as
Postscript, and a document like this email message, which is not.
(Well, at least until computers start to take commands in unrestricted
English...).

Which doesn't have any legal meaning, of course, since the law's
definition isn't phrased in terms of Turing completeness... but that
was the problem with the whole conversation the first time around.

Apologies for diving back in the tarpit.

rst