((element "bikes" "-" "-" (element-content (seq zero-or-more (name one "bike"))) "") (element "bike" "-" "-" (element-content (seq one (name one "frame") (name one-or-more "wheel") (name zero-or-more "brake") (name zero-or-more "lock"))) "") (element "frame" "-" "-" empty "") (element "wheel" "-" "-" empty "") (element "brake" "-" "-" empty "") (element "lock" "-" "-" empty "") (attribute "bikes" ()) (attribute "bike" (("kind" ("mountain-bike, racer-bike, tourist-bike, other") "tourist-bike"))) (attribute "frame" (("frame-number" "CDATA" "#REQUIRED"))) (attribute "wheel" (("size" "CDATA" "#REQUIRED") ("tube-kind" "CDATA" "#IMPLIED"))) (attribute "brake" (("kind" "CDATA" "#IMPLIED") ("brand" "CDATA" "#IMPLIED"))) (attribute "lock" (("brand" "CDATA" "#IMPLIED") ("insurance-approved" ("true" "false") "#REQUIRED"))) (entity "Number" "CDATA") (entity "Boolean" "(true | false)"))