Ariadne's thread (logic)

At present, it is most prominently applied to Sudoku puzzles, used to attempt values for as-yet-unsolved cells.

The medium of the thread for puzzle-solving can vary widely, from a pencil to numbered chits to a computer program, but all accomplish the same task.

Note that as the compilation of Ariadne's thread is an inductive process, and due to its exhaustiveness leaves no room for actual study, it is largely frowned upon as a solving method, to be employed only as a last resort when deductive methods fail.

Due to the massive depth of many games, most algorithms cannot afford to apply Ariadne's thread entirely on every move due to time constraints, and therefore work in tandem with a heuristic that evaluates game states and limits a breadth-first search only to those that are most likely to be beneficial, a trial-and-error process.

Even circumstances where the concept of "solution" is not so well defined have had Ariadne's thread applied to them, such as navigating the World Wide Web, making sense of patent law, and in philosophy; "Ariadne's Thread" is a popular name for websites of many purposes, but primarily for those that feature philosophical or ethical debate.