97 

    97 

    98 # ~~~~~~ role

    98 # ~~~~~~ role

    99 role = element role { role.content }

    99 role = element role { role.content }

   100 

   100 

   101 role.content = "author" | "illustrator" | "publisher" | "packager"

   101 role.content = "author" | "illustrator" | "publisher" | "packager"

   102 

   103 

   103 # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ source ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

   104 # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ source ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

   104 

   105 

   105 source = element source {

   106 source = element source {

   106    (  (attribute type { "book" }, source.content.book)

   107    (  (attribute type { "book" }, source.content.book)