@dmai In fact, after further investigation, this counterexample even violates “read atomicity” (RA), coined by Bailis et al. at SIGMOD’14 Scalable atomic visibility with RAMP transactions | Proceedings of the 2014 ACM SIGMOD International Conference on Management of Data. RA is even weaker than transactional causal consistency, which is in turn weaker than Snapshot Isolation.
The attached picture visualizes why our example violates RA (the red cycle). See Fig.2 (b) in https://dl.acm.org/doi/10.1145/3360591 for the formal definition, where t1, t3, and t2 are mapped to txn4, txn6, and txn13 in our case, respectively.
PS! txn11 in our example has only one operation r(10,3). Sorry for the bad formatting in previous comments.
