A conversion process, built into Relativity DBMS, that is used to synthesize a COBOL data item using the value or values of one or more other COBOL data items within the same COBOL file definition (FD). The other COBOL data items, which may include a previously defined internal function, are specified as arguments to internal functions. The result of the internal function is used as the value for the synthesized COBOL data item, also known as a function item. Unlike a transform, an internal function may operate on more than one COBOL data item. Compare to transform.