context ContinuityOfCareDocument
inv: self.documentationOf->forAll(docof : POCDMT000040DocumentationOf  | 
		docof.serviceEvent.oclIsUndefined() or 
		(not docof.serviceEvent.nullFlavor.oclIsUndefined()) or
		docof.serviceEvent.effectiveTime.oclIsUndefined() or 
		(not docof.serviceEvent.effectiveTime.nullFlavor.oclIsUndefined()) or
		(
			not docof.serviceEvent.effectiveTime.low.oclIsUndefined() and 
			not docof.serviceEvent.effectiveTime.high.oclIsUndefined()
		)
)