[rules-users] question on drools and method calls on facts

I'm under the impression that in the action clause of a rule you should only do one of the following: 1) Set a property on a Fact 2) Retract a Fact 3) Insert (Assert) a new Fact 4) Modify an existing Fact However in some of the examples in the documentation it shows calling methods other than bean property getters and setters. I was wondering if what other peoples opinions are on whether you should be doing more than the 4 things I listed above in a then clause of a rule. Thanks, SG -----Message Disclaimer----- This e-mail message is intended only for the use of the individual or entity to which it is addressed, and may contain information that is privileged, confidential and exempt from disclosure under applicable law. If you are not the intended recipient, any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by reply email to Connect(a)principal.com and delete or destroy all copies of the original message and attachments thereto. Email sent to or from the Principal Financial Group or any of its member companies may be retained as required by law or regulation. Nothing in this message is intended to constitute an Electronic signature for purposes of the Uniform Electronic Transactions Act (UETA) or the Electronic Signatures in Global and National Commerce Act ("E-Sign") unless a specific statement to the contrary is included in this message. While this communication may be used to promote or market a transaction or an idea that is discussed in the publication, it is intended to provide general information about the subject matter covered and is provided with the understanding that The Principal is not rendering legal, accounting, or tax advice. It is not a marketed opinion and may not be used to avoid penalties under the Internal Revenue Code. You should consult with appropriate counsel or other advisors on all matters pertaining to legal, tax, or accounting obligations and requirements.