Solution 9.10.3.6 S G a = a G @G @a = a abK (s + a)(s+ b) @ @a abK s 2 +(a + b)s + ab = s 2 +(a+ b)s + ab bK  ;ab(s + b)K (s 2 +(a + b)s + ab) 2 + bK s 2 +(a+ b)s+ ab  = s 2 +(a + b)s + ab  ;a(s + b) (s 2 +(a + b)s+ ab) 2 + 1 s 2 +(a+ b)s+ ab  = s 2 +(a + b)s + ab " ;as;ab+ s 2 +(a + b)s + ab (s 2 +(a+ b)s + ab) 2 # = s(s + b) s 2 +(a+ b)s + ab : T c (s) = abK s 2 +(a + b)s + ab 1+ abK s 2 +(a + b)s + ab = abK s 2 +(a+ b)s +(ab+ abK) : S T c a = a T c @T c @a = a abK s 2 +(a+ b)s + ab(1 + K) @ @a abK s 2 +(a + b)s + ab(1 + K) = s 2 +(a+ b)s + ab(1 + K) bK  ;abK[s + b(1 + K)] [s 2 +(a+ b)s + ab(1 + K)] 2 + bK s 2 +(a + b)s+ ab(1 + K)  = s 2 +(a + b)s + ab(1 + K)  ;a[s + b(1 + K)] [s 2 +(a + b)s + ab(1 + K)] 2 + 1 s 2 +(a + b)s+ ab(1 + K)  = s 2 +(a + b)s + ab(1 + K) " ;as;ab(1 + K)+s 2 +(a + b)s + ab(1 + K) [s 2 +(a + b)s + ab(1 + K)] 2 # = s(s + b) s 2 +(a+ b)s + ab(K +1) S G K = K G @G @K = K abK (s + a)(s+ b) @ @K abK s 2 +(a + b)s + ab = s 2 +(a+ b)s + ab ab  ab (s 2 +(a + b)s + ab)  = 1 S T c K = K T c @T c @K = K abK s 2 +(a+ b)s + ab(1 + K) @ @K abK s 2 +(a + b)s + ab(1 + K) = s 2 +(a+ b)s + ab(1 + K) ab  ;abK(ab) [s 2 +(a+ b)s + ab(1 + K)] 2 + ab s 2 +(a + b)s+ ab(1 + K)  = s 2 +(a + b)s + ab(1 + K)  ;abK (s 2 +(a + b)s + ab(1 + K)) 2 + 1 s 2 +(a+ b)s+ ab(1 + K)  = s 2 +(a + b)s + ab(1 + K) " ;abK + s 2 +(a+ b)s + ab + abK) (s 2 +(a + b)s + ab(1 + K)) 2 # = s 2 +(a + b)s+ ab s 2 +(a+ b)s + ab(K +1)