A process algebraic view of Linda coordination primitives

The main Linda coordination primitives (asynchronous communication, read operation, nonblocking in/rd predicates) are studied in a process algebraic setting. A lattice of eight languages is proposed, where its bottom element L is a process algebra differing from CCS only for the asynchrony of the output operation, while all the other languages in the lattice are obtained as extension of this basic language by adding some of the Linda coordination primitives. The observational semantics for these languages are all obtained as the coarsest congruences contained in the barbed semantics, where only tuples are observable. The lattice of the eight languages collapses to a smaller four-points lattice of different bisimulation-based semantics. Notably, for L this semantics is the standard notion of strong bisimulation, where inputs and outputs/tuples are treated symmetrically.