1 <!DOCTYPE doc [ 2 <!ELEMENT doc (a, b, c, b, c, d) > 3 <!ELEMENT a EMPTY> 4 <!ELEMENT b EMPTY> 5 <!ELEMENT c EMPTY> 6 <!ELEMENT d EMPTY> 7 <!ENTITY c "<c/>"> 8 <!ENTITY bc "<b/>&c;"> 9 ]> 10 <doc> 11 <a/> 12 &bc; 13 &bc; 14 <d/> 15 </doc> 16
