G1c-realtime #0
Let:
  T1 = {:index 2878, :time 7040309512, :type :ok, :process 98, :f :txn, :value [[:r 112 nil] [:r 109 nil] [:r 109 nil] [:append 110 6]]}
  T2 = {:index 2890, :time 7061064773, :type :ok, :process 135, :f :txn, :value [[:r 110 [2 6]]]}
  T3 = {:index 2900, :time 7073769390, :type :ok, :process 216, :f :txn, :value [[:append 109 12] [:append 112 12]]}
  T4 = {:index 2828, :time 6952055454, :type :ok, :process 98, :f :txn, :value [[:append 109 3] [:r 111 [1]] [:append 111 2]]}
  T5 = {:index 2858, :time 7015597340, :type :ok, :process 98, :f :txn, :value [[:r 111 [1 2]] [:append 111 15]]}

Then:
  - T1 < T2, because T2 observed T1's append of 6 to key 110.
  - T2 < T3, because T2 completed at index 2890, 0.002 seconds before the invocation of T3, at index 2895.
  - T3 < T4, because T4 appended 3 after T3 appended 12 to 109.
  - T4 < T5, because T5 appended 15 after T4 appended 2 to 111.
  - However, T5 < T1, because T5 completed at index 2858, 0.000 seconds before the invocation of T1, at index 2859: a contradiction!