A. C. Cem Say, Abuzer Yakaryılmaz, "Computation with multiple CTCs of fixed length and width," Natural Computing, Vol. 11, No. 4, pp. 579-594, 2012. doi: 10.1007/s11047-012-9337-6, Theorem 10: The expression for the infinite sum is wrong and the sum should equal 4, which causes the bound for the expected runtime to be higher (but still a constant).
A. C. Cem Say, Abuzer Yakaryılmaz, "Finite state verifiers with constant randomness," Logical Methods in Computer Science, Vol. 10(3:6)2014, pp. 1-17: The proof of Theorem 3.7 is wrong, and we do not know how to prove that statement. Fortunately, we have found a correct proof of Fact 3.6, which is Theorem 6 in https://arxiv.org/pdf/2306.09542
Fırat Kıyak, A. C. Cem Say, “Energy complexity of regular languages,” Theoretical Computer Science, Vol. 982, January 2024, 114291 https://doi.org/10.1016/j.tcs.2023.114291: Inner product notation is consistently wrong throughout Lemma 7. For any s1, s2, replace "<s1>s" with "<s1|s2>".