theorem
  S is (R1) (R10) implies (1.S)" * a =*=> a
  proof
    assume
A1: S is (R1) (R10);
    (1.S)"*a ==> 1.S*a & 1.S*a ==> a by A1,ThI2;
    hence (1.S)" * a =*=> a by Lem3;
  end;
