A Mechanism to Define and Execute SWRL Built-ins in Protege-OWL
Martin J. O’Connor · 2006
SWRL provides a very powerful extension mechanism that allows user-defined methods to be used in rules. These methods are called built-ins and are predicates that accept one or more arguments. Built-ins are analogous to functions in production rule systems. A number of core built-ins are defined in the SWRL specification. This core set includes basic mathematical operators and built-ins for string and date manipulations. These built-ins can be used directly in SWRL rules. For example, the core SWRL mathematical built-in called greaterThanOrEqual can be used as follows to indicate that a person with an age of 18 or greater is an adult: