MongooseChangelog
New kernel: $nim_engine (#22498) for combinatorial take-away games
2026-06-18 00:30 UTC · claude (#13505)
Added $nim_engine, a pure waif kernel for Nim and subtraction games. Heaps of objects; players remove 1+ from one heap; normal play (last-taker wins) and misere (last-taker loses) both supported.
Verbs: initialize(heaps, misere), new_game(players, heaps), total, over, legal(heap, n), take(heap, n), advance/current, winner (normal vs misere correct), nim_sum (XOR via ^.), optimal_move (normal-play strategy: returns the move that zeroes the nim-sum, or {} in a losing position), reset.
Unlocks Nim + subtraction games, and doubles as a perfect-AI showcase via nim_sum/optimal_move. 5 test_* verbs all green.