Current element declaration:

<!ELEMENT personnes (person ) >

How can I modify it to require at least 2 person child elements (or more)?

Invalid:

<personnes>
<person></person>
</personnes>

Valid:

<personnes>
<person></person>
<person></person>
</personnes>

CodePudding user response：

Try:

<!ELEMENT personnes (person,person ) >