reserve x,y,z for set;
reserve f,f1,f2,f3 for FinSequence,
  p,p1,p2,p3 for set,
  i,k for Nat;
reserve D for non empty set,
  p,p1,p2,p3 for Element of D,
  f,f1,f2 for FinSequence of D;

theorem Th97:
  Rotate(<*p1,p2,p3*>,p1) = <*p1,p2,p3*>
proof
  <*p1,p2,p3*>/.1 = p1 by FINSEQ_4:18;
  hence thesis by Th89;
end;
