reserve S, R for 1-sorted,
  X for Subset of R,
  T for TopStruct,
  x for set;
reserve H for non empty multMagma,
  P, Q, P1, Q1 for Subset of H,
  h for Element of H;
reserve G for Group,
  A, B for Subset of G,
  a for Element of G;

theorem Th47:
  for G being UnContinuous TopGroup, F being closed Subset of G
  holds F" is closed
proof
  let G be UnContinuous TopGroup, F be closed Subset of G;
  F" = (inverse_op G).:F by Th9;
  hence thesis by TOPS_2:58;
end;
