The goal of the Generator gen(x) is to derive a set of binary variables c = {c t } T t=1 by sampling from probability scores s = {s t } T s=1 , where c t ∈ [0, 1] indicates whether x t is chosen as a candidate rationale and s t is computed by the multilevel heuristics.
rewards are fed back to the Generator if the Encoder is able to identify candidate sets that are generated randomly, while the Selector is rewarded if the best performing rationale candidate set outperforms the one in the adversary.