Sequential and Concurrent Obje'ct-Oriented Programming

How can the object-oriented model cover concurrent programming as effectively as it addresses sequential computation? The answer proposed in this article suggests that a modest adaptation to the semantics of object-oriented programs may suffice. This includes introducing an explicit notion of procesSor (but not of process, a concept which objectoriented techniques already cover), explicit declarations for "separate'" entities, a new semantics for preconditions on routines handled by different processors, and "'lazy wait" for implicit resynchronization.