Worksheet #5
AStar (A*) Search

                                             Name ______________

1. The next program can be found at /home/atlas1/ai/astar.lsp.  
   Run this program and understand how it works.  If you copy it to your account be
  sure to delete it after you turn in this assignment, as server space is scarce.



2. Write an explanation of what this new search algorithm does.  Describe the workings
   of each function, tell the purpose of the variables...you probably weren't 
   specific and thorough enough in Best-First.  Plus, there are more now.
   Use a word processor or an
   editor unless your handwriting is impeccable.




3. Briefly describe how this search is different from the best-first search.
   Hint: the "heuristic" is now F = G + H.
   Also, what is the technique for avoiding "circular paths"?




4. Using the sheet provided write out a trace from Av to To.