reserve n for non zero Nat,
  j,k,l,m for Nat,
  g,h,i for Integer;

theorem
  for m be Nat holds 2sComplement(m,0) = 0*m
proof
  let m be Nat;
  2sComplement(m,0) = m-BinarySequence |.0.| by Def2
    .= m-BinarySequence(0) by ABSVALUE:2;
  hence thesis by BINARI_3:25;
end;
