TY  - JOUR
SP  - 16
ID  - eprints403
AV  - public
JF  - Proc. of 17th International Workshop on Expressiveness in Concurrency (EXPRESS 2010), Electronic Proceedings in Theoretical Computer Science
Y1  - 2010///
UR  - http://arxiv.org/abs/1011.6430v1
N1  - © F. Banti, R. Pugliese & F. Tiezzi
A1  - Banti, Federico
A1  - Pugliese, Rosario
A1  - Tiezzi, Francesco
SN  - 20752180 
VL  - 41 
PB  - Open Publishing Association 
TI  - A criterion for separating process calculi
T3  - EPTCS
EP  - 30
N2  - 	We introduce a new criterion, replacement freeness, to discern the relative expressiveness of process calculi. Intuitively, a calculus is strongly replacement free if replacing, within an enclosing context, a process that cannot perform any visible action by an arbitrary process never inhibits the capability of the resulting process to perform a visible action. We prove that there exists no compositional and interaction sensitive encoding of a not strongly replacement free calculus into any strongly replacement free one. We then define a weaker version of replacement freeness, by only considering replacement of closed processes, and prove that, if we additionally require the encoding to preserve name independence, it is not even possible to encode a non replacement free calculus into a weakly replacement free one. As a consequence of our encodability results, we get that many calculi equipped with priority are not replacement free and hence are not encodable into mainstream calculi like CCS and pi-calculus, that instead are strongly replacement free. We also prove that variants of pi-calculus with match among names, pattern matching or polyadic synchronization are only weakly replacement free, hence they are separated both from process calculi with priority and from mainstream calculi.
ER  -