A.3.3.CC:4.1 - Select the participants and retained differences

State what the reader must find: a fitting arrangement, a compatible assignment, a range of positions or the configurations to which a law will later apply. Identify the participants and the differences that can change this answer.

Give each variable a meaning and a value range. For a physical position, include the reference frame and unit needed to interpret it. For a relation, identify its participants: a distance needs the two endpoints; a job count needs the particular buffer. A.17 and A.18 supply the Characteristic and Scale vocabulary when the variables are declared as FPF characteristics.

Separate quantities held fixed in the present model from variables to be found. A link length may be a parameter in a rigid-body model and a changing quantity in an elastic model. The distinction follows the modeled use, so a later revision can change it.

Ask whether two arrangements described by the same values can require different answers to the current question. If they can, retain the missing distinction. For example, a pair of queue lengths suffices for occupancy but loses the order of differently treated jobs. State the needed order before attempting the receiving calculation.