theorem
  a^2 * (1/(b^2)) = (a/b)^2
  proof
    a^2 * (1/(b^2)) = a * a * ((1/b) * (1/b)) by XCMPLX_1:102
    .= a * (a * (1/b)) * (1/b)
    .= a * ((a * 1)/b) * (1/b) by XCMPLX_1:74
    .= (a/b) * (a *(1/b))
    .= (a/b) * ((a * 1)/b) by XCMPLX_1:74
    .= (a / b)^2;
    hence thesis;
  end;
