1  <grammar xmlns="http://relaxng.org/ns/structure/1.0">
 2    <start>
 3      <element name="p">
 4        <ref name="inline"/>
 5      </element>
 6    </start>
 7  
 8    <define name="inline">
 9      <zeroOrMore>
10        <choice>
11          <text/>
12          <element name="bold">
13            <ref name="inline"/>
14          </element>
15          <element name="italic">
16            <ref name="inline"/>
17          </element>
18          <element name="span">
19            <optional>
20              <attribute name="style"/>
21            </optional>
22            <ref name="inline"/>
23          </element>
24        </choice>
25      </zeroOrMore>
26    </define>
27  </grammar>