Can not use mod operators (%) in when clause. --------------------------------------------- Key: DROOLS-4902 URL: https://issues.redhat.com/browse/DROOLS-4902 Project: Drools Issue Type: Bug Components: core engine Affects Versions: 7.31.0.Final Reporter: xb l Assignee: Mario Fusco Priority: Major When I study drools , I write a rule use divide operator {code:java} rule "Buzz" salience 2 when $n: Number( this / 5 == 3 ) then System.out.println("Buzz"); end {code} It's OK. But: {code:java} rule "Buzz" salience 2 when $n: Number( this % 5 == 0 ) then System.out.println("Buzz"); end {code} Report parser error: Unable to Analyse Expression this % 5 == 0: The drools document mentioned the same example: Person( age > 100 && ( age % 10 == 0 ) ) % is Multiplicative operators, why parser error?