Non-XML RELAX NG Syntax

element SONG {
  element TITLE { text }
  & element COMPOSER { text }*
  & element PRODUCER { text }*
  & element PUBLISHER { text }?
  & element LENGTH { xsd:duration }
  & element YEAR { xsd:gYear }
  & element ARTIST { text }+
  & element PRICE {
      xsd:string { pattern = "\p{Sc}\p{Nd}+(\.\p{Nd}\p{Nd})?" }
    }?
}