TY - CHAP SN - 3-540-63165-8 ED - Degano, Pierpaolo ED - Gorrieri, Roberto ED - Marchetti-Spaccamela, Alberto N2 - We propose a general approach to define behavioural preorders over process terms by considering the pre-congruences induced by three basic observables. These observables provide information about the initial communication capabilities of processes and about their possibility of engaging in an infinite internal chattering. We show that some of the observables-based pre-congruences do correspond to behavioral preorders long studied in the literature. The coincidence proofs shed light on the differences between the must preorder of De Nicola and Hennessy and the fair/should preorder of Cleaveland and Natarajan and of Brinksma, Rensink and Vogler, and on the rôle played in their definition by tests for internal chattering. EP - 492 ID - eprints353 PB - Springer T2 - Automata, Languages and Programming (ICALP 1997) AV - none T3 - Lecture Notes in Computer Science SP - 482 TI - Basic Observables for Processes Y1 - 1997/// UR - http://dx.doi.org/10.1007/3-540-63165-8_204 M1 - 1256 A1 - Boreale, Michele A1 - De Nicola, Rocco A1 - Pugliese, Rosario ER -