You enter Reality Check equations just like you would enter other equations. Create a variable, open with the Equation Editor, select the Type Reality Check and the Suptype Constraint or Test Input and fill in the equation.
When you select Type Reality Check, you will notice that the Range label changes to TypPrio (this appears near the bottom just to the right of Group). This is a mechanism for filtering Reality Check statements in the Reality Check Control dialog and will be discussed below. You can enter a number for both Type and Priority. The Values that Priority can take on are arbitrary, but 1-10 would be a common prioritization. Type should take on an integer value between 0 and 64. The settings are not available in PLE or PLE Plus.