FUNCTION acyclic_externally_defined_item_relationship 
          (relation : externally_defined_item_relationship, relatives : SET [1:?] OF externally_defined_item, specific_relation : STRING) : BOOLEAN;
 LOCAL       x : SET OF externally_defined_item_relationship;     END_LOCAL;
      IF  relation.relating_item IN  relatives THEN       RETURN  (FALSE);     END_IF;     x := QUERY(edi <* bag_to_set(USEDIN(relation.relating_item, 'EXTERNAL_REFERENCE_SCHEMA.' + 'EXTERNALLY_DEFINED_ITEM_RELATIONSHIP.' + 'RELATED_ITEM')) | specific_relation IN TYPEOF(edi));     REPEAT i := 1 TO HIINDEX(x);       IF NOT acyclic_externally_defined_item_relationship(x[i], relatives + relation.relating_item, specific_relation) THEN         RETURN  (FALSE);       END_IF;     END_REPEAT;     RETURN (TRUE); END_FUNCTION; -- acyclic_externally_defined_item_relationship 
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