离散数学证明题

A→(B∧C),(E→￢F)→￢C,B→(A∧￢S)│-B→E
(1)B (T规则,附加前提)
(2)B→(A∧￢S) (P规则)
(3)A∧￢S (T规则(1)(2))
(4)A (T规则(3))
(5)A→(B∧C) (P规则)
(6)B∧C (T规则(4)(5))
(7)C (T规则(6))
(8)(E→￢F)→￢C (P规则)
(9)￢(E→￢F) (T规则(7)(8))
(10)E∧F (T规则(9))
(11)E (T规则(10))
(12)B→E (CP规则(1)(11))