theorem
  for p being FinSequence holds Seq Shift(p,i) = p
proof
  let p be FinSequence;
A1: dom Seq Shift(p,i) = dom p by Th42;
  for x being object holds
   x in dom p implies (Seq Shift(p,i)).x = p.x by Th44;
  hence thesis by A1;
end;
