[rules-users] logical chain

Folks, Using 4.0.GA I need to have the following logical chain: Having facts F1(), F2(), F3(), F4() I need a rule to be fired when (F1() and F2()) or (F3() and F4()) condition is true, so made a rule: when (or (and F1() F2() ) (and F3() F4() ) ) then ... But it doesn't execute correctly. F.e. it fires when F1() and F4() are inserted although F2() and F4() are not! Please advice is it my incorrect syntax, or a bug....? Thanks, -Sergey ********************** ** LEGAL DISCLAIMER ** ********************** This E-mail message and any attachments may contain legally privileged, confidential or proprietary information. If you are not the intended recipient(s), or the employee or agent responsible for delivery of this message to the intended recipient(s), you are hereby notified that any dissemination, distribution or copying of this E-mail message is strictly prohibited. If you have received this message in error, please immediately notify the sender and delete this E-mail message from your computer.