Every statement in SQLite's own test files is the referee: the engine passes a statement when it prints exactly what SQLite prints. Eight agents built it in one run, landing work only past that referee. Nothing below is typed by hand: it is generated from real runs of the engine and of SQLite.
Each example runs statement by statement through this engine and through SQLite. The outputs are shown as they came back.
The examples above show features, chosen by us. These are statements from SQLite's own test files where the engine still prints something else, as the referee reports them.
Every attempt to land work on main during the run. A land is accepted only if the score does not fall; refused ones never reached main.
Eight agents, each with an area. They claimed work, left notes, and landed past the referee. One was designed to be fallible: it moved fast and checked little, and the referee caught it.