DTD - Adverb Entry

Adverb Entry:

<!ELEMENT advEntry (variants+, modification+, negative?, interrogative?)>
                                                                                
<!ELEMENT variants (#PCDATA)>
<!ELEMENT modification (#PCDATA)>
<!ELEMENT negative EMPTY>
    <!ATTLIST negative type (negative|broad_negative)>
                                                                                
<!ELEMENT interrogative EMPTY>