 Parsons’ theory rests on the difference between the predicates  Cul and Hold. This difference is left to intuition. No axiomatisation of these predicates is given. This is one of the objections made in Zucchi (1999). Zucchi also notes that under certain circumstances it is possible to derive a specific version of the imperfective paradox in Parsons’ theory. A careful discussion of Dowty’ and Parsons’ approaches and a combination of the two systems is contained in Landman (1992).