Crystal Reports for Rational Application Developer Designer Guide
Operators (Crystal syntax)
Arithmetic operators
Comparison operators (Crystal syntax)
Boolean operators (Crystal syntax)
Null fields and how to use IsNull (Crystal syntax)
Business Objects, an SAP company
http://www.businessobjects.com/
Support services
http://www.businessobjects.com/services/support/
Product Documentation on the Web
http://support.businessobjects.com/documentation/