On reasoning with the global time assumption

Concurrency in distributed systems is usually modeled by a nondeterministic interleaving of atomic events. The consequences of this interleaving (or global time) assumption on the specifications and proofs of distributed programs are examined in this paper. A construction for atomic registers is presented; this construction has the surprising property that it is correct with respect to a specification based on partial orders but is incorrect with respect to a naively derived specification based on global time.