We have two primitive sets in this model--the tasks (TASK) and the workstations (STATION). From these two primitive sets, we create two derived sets.

The first derived set, PRED, is a sparse derived set and is based on a cross of the TASK set on itself. The members of this set are the precedence relations amongst the tasks. For instance, the first member of this set is the pair (A,B), indicating task A must precede task B.

The other derived set, TXS, is a dense derived set formed by taking the cross of the task set on the workstation set. We need this set because we will be determining which tasks get assigned to which workstations.