if e.Operand != nil {
		result = e.Operand.analyze(s)
	} else {
		result = e.Not.analyze(s)
	}
	return
}

func (e *ListExpr) analyze(s *Select) (result qProp) {
	for _, ac := range e.Elements {
		result.combine(ac.analyze(s))
	}
	return
}

func (e *ConditionOperand) analyze(s *Select) (result qProp) {
	if e.ConditionRHS == nil {
		result = e.Operand.analyze(s)
	} else {