I think there may be a bug in MVEL 2.0. If I do the following, I get a runtime exception: with (actionCodeSecurity = new ActionCodeSecurity()) { securityCategory = securityCategory, actionCode = "AA", visitTypeConstraint = 1, visitTypeList = "IP, OP" } However, if I remove the comma between IP and OP it works: visitTypeList = "IP OP" Also, it works fine if I do all my assignments without the 'with' clause: actionCodeSecurity = new ActionCodeSecurity() actionCodeSecurity.securityCategory = securityCategory actionCodeSecurity.actionCode = "AA" actionCodeSecurity.visitTypeConstraint = 1 actionCodeSecurity.visitTypeList = "IP, OP" I'm using the version of MVEL that shipped with Drools 5.0 Final build, Eclipse Workbench, May 19, 2009. -- View this message in context: http://www.nabble.com/MVEL-2.0-bug-in-%27with%27-block-tp24261697p2426169... Sent from the drools - user mailing list archive at Nabble.com.