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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def imsiDetachIndication():
 """IMSI DETACH INDICATION Section 9.2.12"""

    a = TpPd(pd=0x5)
    b = MessageType(mesType=0x1)  # 00000001
    c = MobileStationClassmark1()
    d = MobileId()
    packet = a / b / c / d
    return packet