As discussed in §4.3, we adopt a heuristic inference policy for operator selection.
we enumerate each operator and select the operated sentencex 2 which maximizes the criterion: where LM 2 (x 2 ) denotes the probability ofx 2 computed by the language model LM 2 , p(s j |•) is the classifier defined in §4.4.2, and η is a balancing hyper-parameter.