Tree-of-Thoughts (ToT) is a prompting framework for large language models that formalizes problem-solving as a heuristic search over a tree of coherent intermediate reasoning steps, called "thoughts." Unlike linear Chain-of-Thought (CoT), ToT allows a model to generate multiple potential reasoning paths at each step, evaluate their promise using its own or a separate evaluator's judgment, and systematically explore the space using algorithms like breadth-first search or depth-first search. This transforms the model from a fast, associative thinker into a deliberate planner capable of lookahead and backtracking.
