# Compact RELAX NG Grammar for the Atom Extensibility Framework

default namespace = ""
namespace atom = "http://purl.org/atom/ns#"

start = element atom:atom { Property* } | Property

Property = SimpleProp | LiteralProp | ComplexLiteralProp 
SimpleProp = element * { RefAttr | (RefAttr?, Property*) }
LiteralProp = element * { text | (ModeAttr, any) }
ComplexLiteralProp = element * { NonSpecialAttr+, ModeAttr?, any } 

NonSpecialAttr = attribute * - (mode | ref) { text }
RefAttr = attribute ref { xsd:anyURI }
ModeAttr = attribute mode { text }
any = (text | element * { (attribute * { text } | text | any)* })*