ABSTRACT
The Logic Theorist, using the innovative Information Processing Language, a forerunner of the List Processor converted words and phrases into binary-coded symbols, and by comparing and matching symbol strings in a tree search where the root is the hypothesis, each branch is a deduction founded on symbolic logic, and the objective is at a twig of the tree; the proof is the trajectory from root through branch to twig. The top-down proponents’ idea for expert systems was to hard-wire the fundamental operations, collect the knowledge and heuristics of the best practitioners, add means-end analysis to feedback information that a process was on the right track, and then working backwards from the desired result, pick the best paths to success. Deep Blue's victory over Kasparov demonstrated that a top-down approach could defeat a human in a restricted domain, albeit with hardware and software fixes in-between games, and that Kasparov knew this and thus chose his sub-optimal move strategy.
