1<element name="doc" xmlns="http://relaxng.org/ns/structure/1.0"> 2 <interleave> 3 <element name="a"> 4 <empty/> 5 </element> 6 <zeroOrMore> 7 <element name="b"> 8 <empty/> 9 </element> 10 </zeroOrMore> 11 </interleave> 12 <element name="c"> 13 <empty/> 14 </element> 15</element> 16