
theorem
  for n,k be Nat st n >= 1 holds SDDec(DecSD(0,n,k)) = 0
proof
  let n,k be Nat;
  Radix(k) >= 0 + 1 by INT_1:7,RADIX_2:6;
  then Radix(k) |^ n >= 1 by PREPOWER:11;
  then
A1: 0 is_represented_by n,k by RADIX_1:def 12;
  assume n >= 1;
  hence thesis by A1,RADIX_1:22;
end;
