theorem Th53:
  Col(<*<e2>*>,1) = <* 0 *> &
  Col(<*<e2>*>,2) = <* 1 *> &
  Col(<*<e2>*>,3) = <* 0 *>
  proof
A1: len <e2> = 3 by CARD_1:def 7;
    <e2>.1 = 0 & <e2>.2 = 1 & <e2>.3 = 0 by EUCLID_8:def 2;
    hence thesis by A1,Th51;
  end;
