 The solution to the imperfective paradox just outlined makes reference to the intentions of the agent involved in the event; therefore the notion of a goal or intention is built into the system right from the start. Note, however, it does not involve possible worlds, or primitive notions like inertia worlds; instead it is based upon minimal models and non-monotonic reasoning. This yields additional benefits. Firstly, the Event Calculus will compute a minimal model in cases where an integrity constraint can be satisfied. Moreover, the number of construction steps required for this yields a precise complexity measure which (for example) allows us to derive predictions for cognitive processing. Secondly, the non-monotonic nature of the Event Calculus can be used to model the incremental construction of a temporal model with inferences which hold locally at a discourse segment \(s_n\) but which can be undone at some later discourse unit \(s_{n+1}\). This is a necessary prerequisite if we think of interpreting sentences like (56b) from left to right assuming incremental interpretation (see e.g., Baggio and van Lambalgen 2007 and Bott 2010 for implementations of the Event Calculus as a processing model). In the next section we will review psychological and psycholinguistic work on the interpretation of aspect which will provide empirical motivation for the outlined analysis. 