Exhibit 05Adversarial Search

Tic-Tac-Toe

Play Jev yourself, or watch it face a perfect minimax player. Tic-tac-toe is a solved game: perfect play is always a draw, so every loss is a mistake someone can point to.

Partly in scopeBoard-only play is the chess-like planning TypeSafe says suits reasoning models; with tactics from code it is a snap choice. TypeSafe homepage FAQ: “Some tasks requiring extended reasoning, such as complex mathematics or chess-like planning, may be better suited to large reasoning models.
World
State
Decision
Action
New state
Jev plays
Jev is
Context given to Jev

The board, which mark Jev plays, and the empty squares.

Now
Your move · you are X
JevYou
vs You · Board only
0
Jev
0
Draw
0
You
0 gamesblunders 0 / 0 moves

Jev decision

idle
You are X and move first. Click a square.
top left
top center
top right
middle left
Other (5)
Lesson · Adversarial
My move ↔ your best reply
Tic-tac-toe is small enough that minimax solves it completely: from the empty board, perfect play is a draw. That makes every Jev move gradable. A blunder is any move that lowers the perfect-play outcome: a drawn position turned into a lost one, or a won position thrown away. The coach says so. The context levels mirror Missionaries: the board alone, then facts code can check one move ahead for each side (wins, blocks, the opponent's immediate replies, double threats), then the perfect-play result itself. The question is the same as before: how much of good play is judgement, and how much is the lookahead we hand it?