An accumulate with 2 constraints should accept "and", not just "&&" and "," --------------------------------------------------------------------------- Key: DROOLS-1251 URL: https://issues.jboss.org/browse/DROOLS-1251 Project: Drools Issue Type: Enhancement Components: core engine Affects Versions: 6.4.0.Final Reporter: Geoffrey De Smet Assignee: Mario Fusco Priority: Minor Specifically: {code} accumulate( ...; $t : count($assignment); $t > 0 and $t < $weekendLength // FAILS ) {code} {code} accumulate( ...; $t : count($assignment); $t > 0 && $t < $weekendLength // WORKS ) {code} {code} accumulate( ...; $t : count($assignment); $t > 0, $t < $weekendLength // WORKS ) {code} ---- Full reproducer from optaplanner-examples employee rostering example, this rule: {code} // Identical shiftTypes during a weekend rule "identicalShiftTypesDuringWeekend" when $contractLine : BooleanContractLine(contractLineType == ContractLineType.IDENTICAL_SHIFT_TYPES_DURING_WEEKEND, enabled == true, $contract : contract) $employee : Employee(contract == $contract, $weekendLength : weekendLength) ShiftDate(dayOfWeek == DayOfWeek.SUNDAY, $sundayIndex : dayIndex) $shiftType : ShiftType() accumulate( $assignment : ShiftAssignment( weekend == true, weekendSundayIndex == $sundayIndex, employee == $employee, shiftType == $shiftType); $weekendAssignmentTotal : count($assignment); $weekendAssignmentTotal > 0 and $weekendAssignmentTotal < $weekendLength ) then scoreHolder.addSoftConstraintMatch(kcontext, ($weekendAssignmentTotal.intValue() - $weekendLength) * $contractLine.getWeight()); end {code} throws {code} java.lang.IllegalStateException: There are errors in a score DRL: Error Messages: Message [id=1, level=ERROR, path=org/optaplanner/examples/nurserostering/solver/nurseRosteringScoreRules.drl, line=452, column=0 text=[ERR 102] Line 452:40 mismatched input 'and' in rule "identicalShiftTypesDuringWeekend"] Message [id=2, level=ERROR, path=org/optaplanner/examples/nurserostering/solver/nurseRosteringScoreRules.drl, line=0, column=0 text=Parser returned a null Package] --- {code}