Abstract: A reusable software component that enables procedural rules in the form of text to be edited, viewed, checked for valid rule syntax, and evaluated after assigning values to variables during run-time of a compiled host program in such a way that supplements or modifies the procedural logic of that host program. Thereby enabling a computer's behavior to be modified, or helping it to reach some conclusion or result, based on conditions that need not or cannot be pre-determined before run-time and compiled into the host program. This component can be used in either or both a graphical user interface, GUI, mode and/or a non-GUI mode. This component can be associated with other software components, and it can be customized to apply a specific rule syntax.