LOCAL
      x : SET  OF  product_category_relationship;
      local_children : SET OF product_category;
    END_LOCAL;

    REPEAT  i := 1 TO  HIINDEX(children);
      IF  relation.category :=: children[i] THEN
        RETURN  (FALSE);
      END_IF;
    END_REPEAT;
    x := bag_to_set(USEDIN(relation.category, 'PRODUCT_DEFINITION_SCHEMA.' + 'PRODUCT_CATEGORY_RELATIONSHIP.SUB_CATEGORY'));
    local_children := children + relation.category;
    IF  SIZEOF(x) > 0 THEN
      REPEAT i := 1 TO HIINDEX(x);
        IF NOT acyclic_product_category_relationship(x[i], local_children) THEN
          RETURN  (FALSE);
        END_IF;
      END_REPEAT;
    END_IF;
    RETURN (TRUE);