Dear Ben,
Your second example is quite different: it will result in an error,
because in the second example the variable C is bound to a logic
variable. That's a variable which can be bound only once and not changed
again. Just go on reading the Concepts Techniques and Models book ;-)
Best,
Torsten
On Wed, 2003-11-19 at 20:08, Ben Moseley wrote:
> Hi,
>
> A question has occurred to me whilst reading the Concepts Techniques
> and Models book...
>
> On p22 it gives the following as an example of observable
> nondeterminism in Oz:
>
> declare
> C={NewCell 0}
> thread
> C:=1
> end
> thread
> C:=2
> end
>
> There is observable nondeterminism because we can't tell in advance
> what the content of C will be.
>
> But isn't there observable nondeterminism in the declarative concurrent
> subset of Oz by exactly the same argument:
>
> declare C
> thread
> C=1
> end
> thread
> C=2
> end
>
> ... with this example you cannot tell in advance which value C will be
> bound to. Certainly the other binding attempt will fail, but isn't this
> observable nondeterminism nonetheless?
>
> I expect there's a flaw in my argument somewhere - but I can't see it...
>
> --Ben
> -
> Please send submissions to users@mozart-oz.org
> and administriva mail to users-request@mozart-oz.org.
> The Mozart Oz web site is at http://www.mozart-oz.org/.
> Please send bug reports to bugs@mozart-oz.org.
-- Torsten Anders <t.anders@qub.ac.uk> - Please send submissions to users@mozart-oz.org and administriva mail to users-request@mozart-oz.org. The Mozart Oz web site is at http://www.mozart-oz.org/. Please send bug reports to bugs@mozart-oz.org.