<?xml version="1.0" encoding="UTF-8"?>
<!ELEMENT institut (nom, codi, any-academic, curs+)>

<!ELEMENT nom (#PCDATA)>
<!ELEMENT codi (#PCDATA)>
<!ELEMENT any-academic (#PCDATA)>

<!ELEMENT curs (assignatures, alumnes)>
<!ATTLIST curs
    id ID #REQUIRED
    nom CDATA #REQUIRED
>

<!ELEMENT assignatures (assignatura+)>
<!ELEMENT assignatura (nom, hores)>
<!ATTLIST assignatura
    codi ID #REQUIRED
>

<!ELEMENT hores (#PCDATA)>

<!ELEMENT alumnes (alumne+)>
<!ELEMENT alumne (nom, cognoms, data-naixement, email)>
<!ATTLIST alumne
    id ID #REQUIRED
>

<!ELEMENT cognoms (#PCDATA)>
<!ELEMENT data-naixement (#PCDATA)>
<!ELEMENT email (#PCDATA)>