Diletta romana cacciagrano, Flavio Corradini, Frank D. Valencia and Jesus Aranda
Persistence and Testing Semantics

Abstract: 	
In [24] the authors studied the expressiveness of persistence in the
asynchronous pi-calculus (Api) wrt weak barbed-congruence. The study
is incomplete because ignores the issue of divergence. In this paper,
we present an expressiveness study of persistence in the asynchronous
pi-calculus (Api) wrt De Nicola and Hennessy¡Çs testing scenario which
is sensitive to divergence.  Following [24] we consider Api and three
sub-languages of it, each capturing one source of persistence: the
persistent-input calculus (PIApi), the persistent-output calculus
(POApi) and persistent calculus (PApi). In [24] the authors showed
encodings from Api into the semi-persistent calculi (i.e., POApi and
PIApi) correct wrt weak barbed-congruence. In this paper we prove
that, under some general conditions, there cannot be an encoding from
Api into a (semi)-persistent calculus preserving the must testing
semantics.

[24] C. Palamidessi, V. Saraswat, F. Valencia and B. Victor. On the
Expressiveness of Linearity vs Persistence in the Asynchronous Pi
Calculus. LICS 2006:59-68, 2006.