G1c #0
Let:
  T1 = {:index 18880, :time 38732537904, :type :ok, :process 946, :f :txn, :value [[:append 721 7] [:r 720 [2]] [:append 720 5] [:r 721 [1 4 7]]]}
  T2 = {:index 18918, :time 38811454707, :type :ok, :process 823, :f :txn, :value [[:r 721 [1 4 7]] [:r 370 [1 5 7 11 14]] [:append 722 1] [:r 720 nil]]}
  T3 = {:index 18894, :time 38769174439, :type :ok, :process 842, :f :txn, :value [[:r 719 [1]] [:append 722 4] [:append 720 11] [:r 717 [1 2 3]]]}
  T4 = {:index 18932, :time 38823293819, :type :ok, :process 946, :f :txn, :value [[:append 720 14] [:r 720 [2 4 8 11 14]]]}

Then:
  - T1 < T2, because T2 observed T1's append of 7 to key 721.
  - T2 < T3, because T3 appended 4 after T2 appended 1 to 722.
  - T3 < T4, because T4 appended 14 after T3 appended 11 to 720.
  - However, T4 < T1, because T1 appended 5 after T4 appended 14 to 720: a contradiction!