MFC wizard headers

there's something very strange there...
In the wizard-generated headers of an MFC app, myappview.h has no include directives, but uses CMyAppDoc* in the declaration of GetDocument.
If I use the name of my own classes in the file, it causes an error:

Code:

---

// parsysView.h : Schnittstelle der Klasse CParsysView
//
// here's the double compilation block, but no include directives
class CParsysView : public CScrollView
{
protected: // Nur aus Serialisierung erzeugen
        CParsysView();
        DECLARE_DYNCREATE(CParsysView)

// Attribute
public:
        CParsysDoc* GetDocument();      // legal, why??

---

Code:

---

// parsysDoc.h : Schnittstelle der Klasse CParsysDoc
//
// also no includes
class CParsysDoc : public CDocument
{
protected: // Nur aus Serialisierung erzeugen
        CParsysDoc();
        DECLARE_DYNCREATE(CParsysDoc)

// Attribute
public:
        CParagraph* GetNextPar(POSITION &);    // illegal, why??

---