Several entities can use a Function Expression to define their properties as shown in the table below. If a function expression is not used in any entities, the Motion solver treats that function expression as a measurement. These function expressions will be calculated only at the reporting times. The other function expressions are simultaneously calculated with other entities in every solution process.

As shown in the table and figure below, you can use a Function Expression in other entities by following several steps.

Figure 8.41: Steps to use a Function Expression in an entity

Step	Operation
1st step	Open the entity dialog to set the Function Expression. Then, as shown in the figure below, click the   button to open the function list.
2nd step	Select a Function Expression as shown in the figure below. The formulation and name which is defined for the selected Function Expression will be shown in the formula window and the Function Name field, respectively. If the formulation is modified in the formula window, the formulation in the Function Expression will be changed at the same time.
3rd step	Click the Apply button to apply the Function Expression to the entity.

Figure 8.42: How to use a Function Expression in other entities