diff --git a/04_UDEF/MP/main_04_UDEF_e.cpp b/04_UDEF/MP/main_04_UDEF_e.cpp
index daef257..d29b19c 100644
--- a/04_UDEF/MP/main_04_UDEF_e.cpp
+++ b/04_UDEF/MP/main_04_UDEF_e.cpp
@@ -13,6 +13,7 @@ public:
     BinaryOctet(const BinaryOctet &) = default;
     BinaryOctet &operator=(int const &a);
     const BinaryOctet operator--(int);
+    const BinaryOctet operator+(BinaryOctet a);
 };
 
 BinaryOctet::BinaryOctet() {
@@ -22,12 +23,13 @@ BinaryOctet::BinaryOctet() {
     evenParity = true;
 }
 
+
 BinaryOctet::BinaryOctet(int x) {
-        for (int i = 0; i <= bitsPerOctet - 1; i++) {
+    for (int i = 0; i <= bitsPerOctet - 1; i++) {
         int tmp = ((x >> i) & 1);
         bitsAsDigits[i] = (tmp == 1) ? '1' : '0';
     }
-    //TODO: das sollte eigentlich nicht benötigt werden
+    //FIXME: das sollte eigentlich nicht benötigt werden
     std::reverse(std::begin(bitsAsDigits), std::end(bitsAsDigits));
 
     //einsen zählen
@@ -48,31 +50,56 @@ bool operator!=(BinaryOctet a, BinaryOctet b) {
     return true;
 }
 
-const BinaryOctet BinaryOctet::operator--(const int) {
 
+//TODO: this method
+const BinaryOctet BinaryOctet::operator--(const int) {
+    bool over = false;
+    for(int i = bitsPerOctet - 1; i >= 0; --i) {
+        int tmp = bitsAsDigits[i] - '0';
+
+
+
+        bitsAsDigits[i] = static_cast<char>(tmp + '0');
+    }
 
     return *this;
 }
 
-BinaryOctet operator+(BinaryOctet a, BinaryOctet b) {
-    BinaryOctet result;
 
-    for (int i = 0; i < bitsPerOctet; ++i) {
-        if (a.bitsAsDigits[i] == b.bitsAsDigits[i]) result.bitsAsDigits[i] = '0';
-        else result.bitsAsDigits[i] = '1';
+const BinaryOctet BinaryOctet::operator+(BinaryOctet a) {
+    BinaryOctet result;
+    bool over = false;
+    for (int i = bitsPerOctet - 1; i >= 0; --i) {
+        //Arbeitsvariablen anlegen und char in int umwandeln für einfachere Rechnung
+        int tmp;
+        int aI = a.bitsAsDigits[i] - '0';
+        int bI = bitsAsDigits[i] - '0';
+
+
+        if(over) tmp = aI + bI + 1;
+        else tmp = aI + bI;
+        over = false;
+
+
+        if(tmp >= 2) {
+            over = true;
+            if (tmp % 2 == 0) tmp = 0;
+            else tmp = 1;
+        }
+
+        //Umwandlung in char und ins Ergebnis schreiben
+        result.bitsAsDigits[i] = static_cast<char>(tmp + '0');
     }
+    return result;
+}
+
+
+BinaryOctet operator/(BinaryOctet a, BinaryOctet b) {
+    BinaryOctet result;
 
     return result;
 }
 
-BinaryOctet operator+(BinaryOctet a, int b) {
-
-}
-
-BinaryOctet operator/(BinaryOctet a, BinaryOctet b) {
-
-    return a;
-}
 
 BinaryOctet &BinaryOctet::operator=(int const &a) {
     std::string tmp = std::to_string(a);
@@ -82,9 +109,9 @@ BinaryOctet &BinaryOctet::operator=(int const &a) {
     return *this;
 }
 
+
 BinaryOctet doCalculation(BinaryOctet a, BinaryOctet b) {
     BinaryOctet result;
-
     for (; a != b; b--) {
         a = a + 1;
         a = a / b;
@@ -93,6 +120,7 @@ BinaryOctet doCalculation(BinaryOctet a, BinaryOctet b) {
     return result;
 }
 
+
 // for println();
 std::string as_string(BinaryOctet a) {
     std::string result = "(";
@@ -103,20 +131,41 @@ std::string as_string(BinaryOctet a) {
     return result;
 }
 
+
+std::string as_string(BinaryOctet *a) {
+    std::string result = "(";
+    for (char c : a->bitsAsDigits) {
+        result += c;
+    }
+    result += ")";
+    return result;
+}
+
+
 // for std::cout
 std::ostream &operator<<(std::ostream &os, const BinaryOctet &toBePrinted) {
     os << as_string(toBePrinted);
     return os;
 }
 
+
+std::ostream &operator<<(std::ostream &os, BinaryOctet *toBePrinted) {
+    os << as_string(toBePrinted);
+    return os;
+
+}
+
+
 int main(int argc, char **argv) {
     BinaryOctet a = 0b00001111;
     std::cout << a << std::endl;
     BinaryOctet b = 0b00000110;
     std::cout << b << std::endl;
-    std::cout << new BinaryOctet(5) << std::endl;
+    b--;
+    std::cout << b << std::endl;
+    auto *c = new BinaryOctet(5);
+    std::cout << c << std::endl;
     std::cout << a + b << std::endl;
-    //println("result = ", doCalculation(a,b));
     std::cout << "result = " << doCalculation(a, b) << std::endl;
     return 0;
 }