Parallel Juxtaposition for Bulk Synchronous Parallel ML

The BSMLlib is a library for Bulk Synchronous Parallel (BSP) programming with the functional language Objective Caml. It is based on an extension of the�-calculus by parallel operations on a parallel data structure named parallel vector, which is given by intention. An attempt to add a parallel composition to this approach led to a non-confluent calculus [22] and to a restricted form of parallel composition [20]. This paper presents a new, simpler and more general semantics for parallel composition, renamed here parallel juxtaposition, as well as an associated cost model derived from the BSP cost model