theorem Th45:
  for G being BinContinuous TopGroup, F being closed Subset of G,
  a being Element of G holds F * a is closed
proof
  let G be BinContinuous TopGroup, F be closed Subset of G, a be Element of G;
  F * a = (*a).:F by Th16;
  hence thesis by TOPS_2:58;
end;
