Message Sequence Charts (MSCs) are an attractive visual formalism widely used to capture system requirements during the early design stages in domains such as telecommunication software. It is fruitful to have mechanisms for specifying and reasoning about collections of MSCs so that errors can be detected even at the requirements level. We propose,… (More)
Message Sequence Charts (MSCs) are an attractive visual formalism widely used to capture system requirements during the early design stages in domains such as telecommunication software. A standard method to describe multiple communication scenarios is to use message sequence graphs (MSGs). A message sequence graph allows the protocol designer to write a… (More)
Message Sequence Charts (MSCs) are an attractive visual formalism used during the early stages of design in domains such as telecommunication software. A popular mechanism for generating a collection of MSCs is a Hierarchical Message Sequence Chart (HMSC). However , not all HMSCs describe collections of MSCs that can be " realized " as a finite-state… (More)
We tackle a natural problem from distributed computing, involving time-stamps. Let P = fp 1 ; p 2 ; : : :; p N g be a set of computing agents or processes which synchronize with each other from time to time and exchange information about themselves and others. The gossip problem is the following: Whenever a set P P meets, the processes in P must decide… (More)
Our aim is to provide a simple non-interleaved operational semantics for CCS in terms of a model that is easy to understand|asynchronous transition systems. Our approach is guided by the requirement that the semantics should identify the concurrency present in the system in a natural way, in terms of events occurring at independent locations in the system.… (More)
Motivations Aim Study the expressive power of local clocks as a synchronization mechanism in a distributed system.