An expression is a logical notation, defined according to the syntax of FEEL, that evaluates to a single value. It may consist of one or more entities, such as a literal, constant, or variable, interconnected by zero or more operators. In Process, you can also use outputs of other decisions or built-in functions to define an expression.

1. Add a new decision element to the model.
   1. In graph view, click Expand next to Decision on the diagram palette. Select Expression and drag it onto the canvas. Double-click the element to edit its logic. You can also edit the expression's logic from the properties pane; select the element, then select Open Properties , and in the properties pane click Edit next to the Name field.
      Click Close to return to the canvas.
   2. In list view, click Add new decision in the Decisions bar and select Expression from the Create Decision window. See Adding and Ordering Decisions.
2. In the Expression field, press Ctrl+Space to view an auto-suggest menu. You can use any decision outputs, variables, functions, and keywords listed in the menu to form your expression.
3. After the decision logic is complete, click Save to save and validate changes manually. Changes you make within the decision model are also automatically saved and validated from time to time. Errors, if any, are displayed within the decision.