* This example provides a bizarrely-expensive addition operation.
* It assumes the existence of an expensive procedure—say a database
* lookup—to extract the value to be added.  This version uses the
* typical initialize-on-definition approach to implementation.
         DEFINE('XADD(X)','XADD')
         ADDVALUE = CALL_SOME_EXPENSIVE_OPERATION()        :(XADD.END)
XADD     XADD = X + ADDVALUE                               :(RETURN)
XADD.END