Abstract: A user definable mathematical function is implemented on a data processing system including a data terminal. The user definable mathematical function includes a user definable mathematical formula having at least one operand which is as yet unspecified or undetermined, but which will be retrieved from a source or location specified in the mathematical function. Execution of the user defined mathematical function is initiated by a data terminal selector device associated with the user definable mathematical function. Upon execution of the user defined mathematical function, a variable value is retrieved from the specified source and substituted for the unspecified operand in the user defined mathematical formula. The user defined mathematical formula is executed and a result of the execution provided. A method for providing and using such a user definable mathematical function is also provided.

Abstract: A device restrains unwanted movement of neck apparel worn by a wearer along the front portion of a shirt having uniformly spaced fastening buttons. The restraining device is disposed vertically parallel to and proximate an unrestrained portion of the neck apparel. The restraining device slidably engages with a transversely arranged neck apparel member disposed on the unrestrained portion of the neck apparel. The device includes a soft pliable member having first and second elongated buttonhole openings proximate first and second ends of the member. The longitudinal centers of the first and second elongated buttonhole openings are separated a predetermined distance for releasably engaging with first and second uniformly spaced fastening buttons on the front of the shirt of a wearer. The restraining device permits essential vertical movement of the neck apparel along the restraining device, while generally restraining all other movement.