Source : ISO 10303-45
SCHEMA material_property_representation_schema;
         REFERENCE FROM 
         product_property_representation_schema   -- ISO 10303-41
  (property_definition_representation);
         
         REFERENCE FROM 
         shape_dimension_schema   -- ISO 10303-47
  (dimensional_characteristic_representation);
         
         REFERENCE FROM 
         process_property_representation_schema   -- ISO 10303-49
  (action_property_representation,
           
         resource_property_representation);
         
         REFERENCE FROM 
         support_resource_schema   -- ISO 10303-41
  (label,
           
         text);
         
TYPE characterized_property_representation =
         
         
         SELECT
            (action_property_representation, 
    dimensional_characteristic_representation, 
    property_definition_representation, 
    resource_property_representation);
         END_TYPE; 
         
ENTITY data_environment;
           name : label;
           description : text;
           elements : SET[1:?] OF characterized_property_representation;
         
         END_ENTITY;
ENTITY data_environment_relationship;
           name : label;
           description : text;
           relating_data_environment : data_environment;
           related_data_environment : data_environment;
         
         END_ENTITY;
ENTITY material_dimensional_characteristic_representation
           SUBTYPE OF (dimensional_characteristic_representation);
           dependent_environment : data_environment;
         
         END_ENTITY;
ENTITY material_property_representation
           SUBTYPE OF (property_definition_representation);
           dependent_environment : data_environment;
         
         END_ENTITY;
         END_SCHEMA;  -- material_property_representation_schema