gistfile1.scala

    def smPrimitives(c: CharacteristicRule): List[DataItemID] = c match {
      case Not(r)      => smPrimitives(r)
      case And(r1, r2) => smPrimitives(r1) ++ smPrimitives(r2)
      case Orr(r1, r2) => smPrimitives(r1) ++ smPrimitives(r2)
      case SimpleCharacteristicRule(ce) => ce match {
        case GroupComparison(lhs, _, rhs) => List(lhs)
        case _ => Nil
      }
    }

    case def smPrimitives(c: CharacteristicRule): List[DataItemID] = {
      Not(r)      => smPrimitives(r)
      And(r1, r2) => smPrimitives(r1) ++ smPrimitives(r2)
      Orr(r1, r2) => smPrimitives(r1) ++ smPrimitives(r2)
      SimpleCharacteristicRule(ce) => ce match {
        case GroupComparison(lhs, _, rhs) => List(lhs)
        case _ => Nil
      }
    }