1 greedily by computing g t = argmax gt P (g t |g <t , x, z p ) with the plan decoder (a GRU).
at time step t, the plan decoder makes a binary prediction for each input item by estimating P (d i ∈ g t |g <t , x, z p ): where σ denotes the sigmoid function, h i is the vector of input item d i , and h p t is the hidden state of the plan decoder.