reserve m,j,p,q,n,l for Element of NAT;
reserve e1,e2 for ExtReal;
reserve i for Nat,
        k,k1,k2,j1 for Element of NAT,
        x,x1,x2,y for set;
reserve p1,p2 for FinSequence;
reserve q,q1,q2,q3,q4 for FinSubsequence,
        p1,p2 for FinSequence;
reserve l1 for Nat,
        j2 for Element of NAT;

theorem
  for q being FinSubsequence holds Seq q = Seq Shift(q,i)
proof
  let q be FinSubsequence;
A1: dom Seq q = dom Seq Shift(q,i) by Th55;
  for x being object holds
   x in dom Seq q implies (Seq Shift(q,i)).x = (Seq q).x by Th57;
  hence thesis by A1;
end;
