reserve x, y for set;
reserve D for non empty set;
reserve UN for Universe;
reserve C for Category;
reserve O for non empty Subset of the carrier of C;
reserve G,H for AddGroup;
reserve V for Group_DOMAIN;

theorem
  Trivial-addLoopStr in MidOpGroupObjects(UN)
proof
  Trivial-addLoopStr in the carrier of AbGroupCat(UN) by Th36;
  hence thesis;
end;
