Indeed this would need to predefine a maximum number of states. This work referenced also in the OP paper uses recurrent neural nets and a genetic algorithm to

Indeed this would need to predefine a maximum number of states. This work referenced also in the OP paper uses recurrent neural nets and a genetic algorithm to evolve the minimal number of states needed: https://arxiv.org/abs/2111.00600 https://arxiv.org/abs/2111.00600