I'm new to the rules syntax and a bit frustrated with trying to learn it. I've reviewed the docs but keep running into the same issue. I have a parent object, Message, that contains an Order. An Order has a status that I want to test. So looking at the documentation and taking my best guess I've created a rule as follows:

rule "Order not Accepted"

when

$m : Message( state == MessageState.RELEASING, order.requestStatus == RequestStatus.ACCEPT )

then

...

end

The problem is that when I start my application I get a compilation error.

Caused by:

org.drools.rule.InvalidRulePackage: [54,48]: unknown:54:48 Unexpected token ','[54,70]: unknown:54:70 mismatched token: [@427,1915:1916='==',<75>,54:70]; expecting type LEFT_PAREN[54,95]: unknown:54:95 mismatched token: [@434,1940:1940=')',<37>,54:95]; expecting type LEFT_PAREN

at org.drools.rule.Package.checkValidity(Package.java:368)