<xsd:complexType name="PPV_PCA.PROBLEM.CONTENT"> <xsd:sequence> <xsd:element ref="PRB" minOccurs="1" maxOccurs="1" /> <xsd:element ref="NTE" minOccurs="0" maxOccurs="unbounded" /> <xsd:element ref="VAR" minOccurs="0" maxOccurs="unbounded" /> <xsd:element ref="PPV_PCA.PROBLEM_ROLE" minOccurs="0" maxOccurs="unbounded" /> <xsd:element ref="PPV_PCA.PROBLEM_OBSERVATION" minOccurs="0" maxOccurs="unbounded" /> </xsd:sequence> </xsd:complexType>