try 1 cannibal rows west to east alone 3 2 0 1
	Moved to 3 2 0 1 e
      try 1 cannibal rows east to west alone 3 3 0 0
      BACKTRACK from:3 2 0 1
      try 2 cannibals row west to east 3 1 0 2
	Moved to 3 1 0 2 e
      ...

   Solution path is
   state(3,3,0,0,w)
   state(2,2,1,1,e)
   state(2,3,1,0,w)
   state(2,1,1,2,e)
   state(2,2,1,1,w)
   state(1,1,2,2,e)
   state(1,2,2,1,w)
   state(1,0,2,3,e)
   state(1,1,2,2,w)
   state(0,0,3,3,e)

PROLOG FTP LIBRARY: PROLOG does not contain a built-in "member" predicate, so you will have to include one in your database. You can ftp a file with some useful PROLOG predicates from the CPSC 352 FTP Site. There are several PROLOG sample programs available there as well. Feel free to have a look there and borrow whatever is helpful.

HANDIN DIRECTIONS:

• Hand in a printed copy of your PROLOG program. It should contain comments that describe the problem and your solution and document your predicate definitions.

• Hand in a copy of your Unix xterm session showing a trace of your PROLOG session. The trace should show the progress of the search as well as the solution path.

  To make a copy of your PROLOG sessions, you use the Unix script command:

   $ script sfilename               //  a copy of your session will be saved
   bash$ prolog                     //  script changes the unix prompt
   ?-                               // Do your PROLOG thing.
   ?- ...
   ?- ^D                            // exit PROLOG
   bash$ ^D                         // control-D exits from script
   Script done. File is sfilename.
   $lpr sfilename                   // print your script and annotate it