ABSTRACT
T concurrent and distributed systems. It is a par-ticular kind of shared-memory style: many independently executing information processing units consume data from a common substrate and produce data onto that, or other, substrate. These substrates are called tuple, or data, spaces. There are three primitives for data manipulation: (1) out, or put, which places a piece of data from inside the unit onto a data space; (2) in, or get, which takes a piece of data from the data space and into the unit; and read, or sense, which reads a piece of data from the data space into the unit without removing it.
