The gross code's depth-8 syndrome cycle has circuit distance 10

Bravyi et al. conjectured that their depth-8 syndrome cycle for the [[144,12,12]] gross code has circuit distance 10. We prove it. In their noise model and for every number of noisy cycles, no set of nine or fewer faults causes an undetected logical error of either Pauli type, and we give explicit ten-fault logical errors of both types. When we released our data on 15 October 2026, the best reported bounds for X-type faults were 9 ≤ d_circ ≤ 12, at 12 rounds; since then, Crocker and Pan have reported the value 10 in both bases, for 12 noisy cycles and for every number of cycles up to 12, respectively. For the same family of circuits we show that the [[90,8,10]] and [[108,8,10]] cycles have circuit distance 8 for every number of cycles, extending values reported for fixed numbers of rounds; for [[72,12,6]] we confirm the known value 6. We also find that, for three of these codes, Google's Tesseract test circuits have the same detector-error-model columns as the depth-8 cycle once restricted to the detectors of the memory basis, for every number of rounds we checked, so circuit-distance results carry over between the two at those round counts. The lower bounds combine 607 SAT refutations, each with a DRAT proof, with exhaustive enumerations of extended-code logicals that carry no certificate. Finally, we independently confirm two results that others reported first: the [[360,12]] bivariate bicycle code has distance 24, and the left-right gross-code circuit of Strikis, Browne and Beverland, as reconstructed from their figures, has circuit distance 11. All code, formulas, proofs and fault sets are available at doi:10.5281/zenodo.23394575.