If the selected entity e t is new (e t ∈ E t−1 ), the hidden state of the tracking model is updated with the embeddingē of entity e t as input.
if entity e t has already appeared in the past (e t ∈ E t−1 ) but is not identical to the previous one (e t = e t−1 ), we use h ENT s (i.e., the memory state when this entity last appeared) to fully exploit the local history of this entity.