vocabulary <http://flandersmake.be/cdf/vocabulary/immutable#> as immutable {
	
	extends <http://www.w3.org/2001/XMLSchema#> as xsd

	aspect Thing [
		key hasUUID
		restricts scalar property hasUUID to exactly 1 
	]
	
	scalar property hasUUID [
		domain Thing
		range xsd:string
		functional
	]
}