There are nine built-in Progress.BPM.Filter.* classes that implement the
Progress.BPM.Filter.ITaskFilter interface. Each of these classes implements a simple filter based on one property of the
Progress.BPM.Task class, and all the classes are in the
Progress.BPM.Filter namespace. The filters fall into two categories: filters that act on a
Task property whose type is CHARACTER (as shown in
Table 137), and those that act on DATETIME properties. All of the filters in the same category work in the same manner.