
theorem DinoDom:
  for f being FinSequence,
      i,j being Nat,
      a,b being object holds
    dom Replace (f,i,j,a,b) = dom f
  proof
    let f be FinSequence,
        i,j be Nat,
        a,b be object;
    dom (f+*(i,a)) = dom f by FUNCT_7:30;
    hence thesis by FUNCT_7:30;
  end;
