 enum TwoNumberSigns {
     case Positive
     case Negative
-    case Different
+    case LeftPositive
+    case RightPositive
     
     static func signsForTwoBigIntegers(a:BigInteger, b:BigInteger) -> TwoNumberSigns {
         switch a.isNegative {

}

func +(left:BigInteger, right:BigInteger) -> BigInteger {
    return left.add(right)
}


            return .Negative
        case false where b.isNegative == false:
            return .Positive
        case false where b.isNegative == true:
            return .LeftPositive
        case true where b.isNegative == false:
            return .RightPositive
        }
        
    }
}

