It is established that durational and structural aspects of actions can in general not be modeled in interleaving semantics, even when a time-consuming action is represented by a pair of instantaneous events denoting its start and finish. By means of a series of counterexamples it is shown that, for any $n$, it makes a difference whether actions are split in $n$ or in $n+1$ parts.

Modes of Computation (acm F.1.2), Semantics of Programming Languages (acm F.3.2), Formal Definitions and Theory (acm D.3.1)
Modes of computation (nondeterministic, parallel, interactive, probabilistic, etc.) (msc 68Q10), Semantics (msc 68Q55)
CWI
Department of Computer Science [CS]

van Glabbeek, R.J, & Vaandrager, F.W. (1995). The difference between splitting in n and n + 1. Department of Computer Science [CS]. CWI.