L0 = <http://www.simantics.org/Layer0-1.1>

L0.valid ==> "Boolean" <R L0.HasProperty : L0.FunctionalRelation
L0.required ==> "Boolean" <R L0.HasProperty : L0.FunctionalRelation
L0.default ==> "Boolean" <R L0.HasProperty : L0.FunctionalRelation
L0.readOnly ==> "Boolean" <R L0.HasProperty : L0.FunctionalRelation
L0.validator ==> "StringInputValidator" <R L0.HasProperty : L0.FunctionalRelation

L0.Entity
  >-- L0.hasStandardResource ==> "Resource" <R L0.HasProperty : L0.FunctionalRelation
    L0.HasDescription "The backend resource for standard graph-based Variables."
  >-- L0.domainProperties ==> "VariableMap" <R L0.HasProperty : L0.FunctionalRelation 
    L0.HasDescription "Returns a map of all domain properties of the entity."
  >-- L0.domainChildren ==> "VariableMap" <R L0.HasProperty : L0.FunctionalRelation 
    L0.HasDescription "Returns a map of all domain children of the entity."
  >-- L0.valueAccessor ==> "ValueAccessor" <R L0.HasProperty : L0.FunctionalRelation 
    L0.HasDescription "Returns an interface for accessing the value."
  @L0.assert L0.hasStandardResource L0.Functions.hasStandardResource
  @L0.assert L0.domainProperties L0.Functions.standardChildDomainProperties
  @L0.assert L0.domainChildren L0.Functions.standardChildDomainChildren

L0.Value
  @L0.assert L0.domainProperties L0.Functions.standardPropertyDomainProperties
  @L0.assert L0.domainChildren L0.Functions.standardPropertyDomainChildren
  
L0.Relation
  >-- L0.classifications ==> "[String]" <R L0.HasProperty : L0.FunctionalRelation 
    L0.HasDescription "Returns a set of classifications for this property."
  @L0.assert L0.classifications L0.Functions.standardClassifications
  @L0.assert L0.required L0.Functions.standardRequiredValue
  @L0.assert L0.readOnly L0.Functions.standardReadOnlyValue
  @L0.assert L0.valid L0.Functions.standardValidValue
  @L0.assert L0.default L0.Functions.standardDefaultValue
  @L0.assert L0.validator L0.Functions.standardValidator
  
L0.PropertyRelation  
  @L0.assert L0.domainProperties L0.Functions.standardPropertyDomainProperties
  @L0.assert L0.domainChildren L0.Functions.standardPropertyDomainChildren
  @L0.assert L0.valueAccessor L0.Functions.standardValueAccessor