1 <!ENTITY % c SYSTEM "http://example.org/c/c.dtd"> 2 %c; 3 <!ENTITY % a SYSTEM "http://example.org/a/a.dtd"> 4 %a; 5 <!ENTITY % b SYSTEM "http://example.org/b/b.dtd"> 6 %b; 7 <!ELEMENT cab (c, a, b)> 8