To be able to use the result of complex verifications as condition for a rule, you can use PHP functions of the rule condition function type (See section PHP functions). In the rule's form mask in the Condition section, select Query a function in the drop-down list.

Query a function
Select the rule condition function you want to use as a condition for your rule in the condition picklist. You can define if the rule is to be executed for the return value True or False. By default, the value True is used. Furthermore, the call parameters of the function can be linked with fixed values or with values from the process table, subtables, form elements or JobRouter variables.