30  & (identifier, identifier?)?

    30  & identifier*

   546 identifier = element identifier {

   546 # ~~~~~~ identifier

   547    (attribute type { "ean" }, xsd:token {pattern = "\d{13}"})

   547 identifier = identifier.uri | identifier.ean

   548  | (attribute type { "uri" }, xsd:anyURI)

   548 

   549 }

   549 # ~~~~~~ identifier.uri

   550 

   550 identifier.uri = element identifier { identifier.uri.attributes }

   551 identifier.ean = element identifier {

   551 

   552    attribute type { "ean" }, xsd:token {pattern = "\d{13}"}

   552 identifier.uri.attributes =

   553 }

   553    type_uri.attribute

   554 

   554  & for.attribute?

   555 identifier.uri = element identifier {

   555 type_uri.attribute = attribute type { "uri" }, xsd:anyURI

   556    attribute type { "uri" }, xsd:anyURI

   556 

   557 }

   557 # ~~~~~~ identifier.ean

   558 identifier.ean = element identifier { identifier.ean.attributes }

   559 

   560 identifier.ean.attributes =

   561    type_ean.attribute

   562  & for.attribute?

   563 type_ean.attribute = attribute type { "ean" }, xsd:token {pattern = "\d{13}"}