Henzinger, Monika H, Thomas A Henzinger, and Peter Kopke. “Computing Simulations on Finite and Infinite Graphs.”https://doi.org/10.1109/SFCS.1995.492576__In Proceedings of IEEE 36th Annual Foundations of Computer Science, 453–62. IEEE, 1995.https://doi.org/10.1109/SFCS.1995.492576 .