[cap-talk] Is "Authority" Subjective?

[Jonathan S. Shapiro]

On Sat, 2007-06-23 at 08:43 +0200, Pierre THIERRY wrote:
> Scribit Jonathan S. Shapiro dies 22/06/2007 hora 13:35:
> > Not generally. Yes, there is concurrency in the real system, but the
> > *model* generally assumes a layer at which execution proceeds by some
> > serializable sequence of atomic operations.
> > 
> > The serialization need not be unique, but at least one such
> > serialization has to exist.
> 
> But when the serialization is not unique, you cannot reason on it.

That is not always true. It is true that you cannot reason about the
*particular* sequence, but that is usually not the goal. In practice,
the reasoning tends to take the form:

  (a) all legal sequences are shown to be safe
  (b) the current state is the result of some legal sequence
  therefore the current state is safe

shap
-- 
Jonathan S. Shapiro, Ph.D.
Managing Director
The EROS Group, LLC