Problem with Class scope resolution

[apeachaday]

I have a List class and I am to now add a stack class and use some of the functions from the list class. I put everything together, but I am getting an error that I believe has something to do with the scope of the two classes. Currently there isn't anything in the main because I can't get it to compile without errors. I have included a sample of the errors. The same errors repeat for each instance. I greatly appreciate any comments, hints, or tips provided!

//**********Class Definitions/Function Prototypes**********
class List
{
    public:
        //Typedef declarations
        typedef char ET;//Element Type
        static const ET CAPACITY = 20; //Size of the array

        //Constructor
        List();

        //Class Member Functions
        bool empty();
        void front();
        void end();
        bool insertAfter(ET);
        int getElement();
        int size();
        void erase();
        bool operator==(List &);
        void push(int);
        void pop();
        ET top();
        void full();

        //Friends
        friend ostream &operator<<(ostream &out, const List &l);

    private:
        ET MyAry[CAPACITY];
        int Position; //Points current position
        int Used; //Points to next available position
};

class Stack
{
    public:
        //Stack();

    private:
        List myStack;
};

//Operator Overloads
List operator+(const List &a, const List &b);

int main()
{




}
//**********Function Definitions**********
List::List()
{
    //Set to zero
    Position = 0;
    Used = 0;

    //Zero out array
    for(int i = 0; i < CAPACITY; i++)
    {
        MyAry[i] = 0;
    }
}

bool List::empty()
{
    //Used = 0 is returns true
    return Used;
}

void List::front()
{
    //Sets position to the first location
    Position = 0;
}

void List::end()
{
    //Gets the end position
    if(Used != 0)
    {
        Position = Used - 1;
    }
}

bool List::insertAfter(ET value)
{
    //Checks for position out of bounds
    if(Position + 1 > CAPACITY)
    {
        return false;
    }
    else
    {
        //If used is zero then first element
        if(Used == 0)
        {
            MyAry[Used] = value;
        }
        else
        {
            //Moves everything down to make room for new element
            for(int i = Used; i > Position + 1; i--)
            {
                MyAry[i] = MyAry[i - 1];
            }
            MyAry[Position] = value;
        }

        //Increment
        Position++;
        Used++;

        return true;
    }
}

int List::getElement()
{
    //Returns element at Position
    return Position;
}

int List::size()
{
    //Returns size of the array
    return Used;
}

void List::erase()
{
    //Move all remaining elements down
    for(int i = Position; i < Used; i++)
    {
        MyAry[i] = MyAry[i + 1];
    }

    //Decrement Used
    Used--;
}
ostream &operator<<(ostream &outs, const List &s)
{
    for(int i = 0; i < s.Used; i++)
    {
        outs << s.MyAry[i] << " ";
    }

    return outs;
}

bool List::operator ==(List &l)
{
      if(Used == l.size()
      &&
      MyAry[0]==l.MyAry[0]
      &&
      MyAry[(Used-1)]==l.MyAry[(Used-1)])
        {return 1;}
        else
        {return 0;}
}

List operator +(const List &L1, const List &L2)
{
    List answer;

    answer = L1 + L2;

    return answer;
}

void List::push(int value)
{
    Stack::myStack.end();
    Stack::myStack.InsertAfter(value));
}

void List::pop()
{
    Stack::myStack.end();
    Stack::myStack.erase();
}

ET List::top()
{
    Stack::myStack.end();
    Stack::myStack.getElement();

    return;
}

error: 'List Stack::myStack' is private
error: void List::push(int value)- within this context
error: object missing in reference to 'Stack::myStack'
error: from this location

[vlad from moscow]

Your class List has no such member as myStack. So it is not clear why are you trying access myStack in List's member function definitions. For example

void List::push(int value)
{
    Stack::myStack.end();
    Stack::myStack.InsertAfter(value));
}

[apeachaday]

The instructions were to create a Stack class to go along with the list class we already had. Inside the stack class I was to create a private variable called:
List myStack which was according to my understanding, give myStack access to the functions in List.