<?xml version = "1.0" encoding="iso-8859-1"?>
<!DOCTYPE personen [
<!ELEMENT personen      (person)*>
<!ELEMENT person        (arzt|patient)>
<!ELEMENT arzt          (name, vorname, (strasse, plz, ort)? )>
<!ELEMENT patient       (name, vorname, strasse, plz, ort, diagnosen*)>
<!ELEMENT diagnosen     (diagnose*)>
<!ELEMENT name          (#PCDATA)>
<!ELEMENT vorname       (#PCDATA)>
<!ELEMENT strasse       (#PCDATA)>
<!ELEMENT plz           (#PCDATA)>
<!ELEMENT ort           (#PCDATA)>
<!ELEMENT diagnose      (#PCDATA)>

<!ATTLIST patient 
	pat_id   CDATA                  #REQUIRED
	kennung  (intern|extern|beides) #REQUIRED
	hausarzt IDREF                  #IMPLIED> 	
<!ATTLIST arzt
	lfdnr    ID                     #REQUIRED>
] >
<personen/>

