Early Heuristic Programs
5.1 The Logic Theorist and Heuristic Search
Just prior to the Dartmouth workshop, Newell, Shaw, and Simon had programmed a version of LT on a computer at the RAND Corporation called the JOHNNIAC (named in honor of John von Neumann). Later papers1 described how it proved some of the theorems in symbolic logic that were proved by Russell and Whitehead in Volume I of their classic work, Principia Mathematica.2 LT worked by performing transformations on Russell and Whitehead’s five axioms of propositional logic, represented for the computer by “symbol structures,” until a structure was produced that corresponded to the theorem to be proved. Because there are so many different transformations that could be performed, finding ...