theorem Th46:
  for G being BinContinuous TopGroup, F being closed Subset of G,
  a being Element of G holds a * F is closed
proof
  let G be BinContinuous TopGroup, F be closed Subset of G, a be Element of G;
  a * F = (a*).:F by Th15;
  hence thesis by TOPS_2:58;
end;
