
theorem Th11:
  for k be Nat st k >= 2 holds SD_Add_Data(Radix(k),k) = 0
proof
  let k be Nat;
  assume k >= 2;
  then
A1: SD_Add_Carry(Radix(k)) = 1 by Th10;
  SD_Add_Data(Radix(k),k) = Radix(k) - SD_Add_Carry(Radix(k)) * Radix(k)
  by RADIX_1:def 11
    .= Radix(k) - Radix(k) by A1;
  hence thesis;
end;
