AbstractPYTHON is an expert system for recognizing and performing squeeze plays, an advanced strategy in the game of bridge. It performs, in its limited domain, at a truly expert standard, comparable to players of national ranking. The development of PYTHON illustrates how a well-constructed logical solution to a simple case of a problem can be extended in several different directions, yielding new results and a powerful program. PYTHON's core recognizes when a simple squeeze exists according to well-established theory. The core was extended to handle more complicated squeezes, also described by theory, making PYTHON's performance truly expert. The core was also extended to generate a plan for playing squeezes which has been successfully ex...