theorem Th92:
  not 3 divides b|^2 + 1 & not 3 divides b|^2 - 2
  proof
    A1: (b|^2 + 1) = 3 + (b|^2 - 2);
      not 3 divides 1|^2 + b|^2 by INT_2:27,Th91;
    hence thesis by A1,WSIERP_1:4;
  end;
