
theorem Hartr 2 = <*1/2,1/2*>
  proof
    reconsider f = Hartr 2 as 2-element complex-valued FinSequence;
    reconsider g = RHartr 2 as 2-element complex-valued FinSequence;
    len f = 2 & len g = 2 by CARD_1:def 7; then
    dom f = Seg 2 & dom g = Seg 2 by FINSEQ_1:def 3; then
    1 in dom f & 2 in dom f; then
    f.1 = (g.1)" & f.2 = (g.2)" by VALUED_1:def 7;
    hence thesis by RH2;
  end;
