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+;;;_* landmark.el --- Landmark learning neural network
+;; Copyright (C) 1996 Free Software Foundation, Inc.
+
+;; Author: Terrence Brannon <brannon@rana.usc.edu>
+;; Maintainer: same
+;; Created: December 16, 1996 - first release to usenet
+;; Keywords: gomoku neural network adaptive search chemotaxis
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING.  If not, write to the
+;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
+
+;;;_* Usage
+;;; Just type 
+;;;   M-x eval-current-buffer
+;;;   M-x lm-test-run
+
+;;;_* Commentary
+;;; Lm is a relatively non-participatory game in which a robot
+;;; attempts to maneuver towards a tree at the center of the window
+;;; based on unique olfactory cues from each of the 4 directions. If
+;;; the smell of the tree increases, then the weights in the robot's
+;;; brain are adjusted to encourage this odor-driven behavior in the
+;;; future. If the smell of the tree decreases, the robots weights are
+;;; adjusted to discourage a correct move.
+
+;;; In layman's terms, the search space is initially flat. The point
+;;; of training is to "turn up the edges of the search space" so that
+;;; the robot rolls toward the center.
+
+;;; Further, do not become alarmed if the robot appears to oscillate
+;;; back and forth between two or a few positions. This simply means
+;;; it is currently caught in a local minimum and is doing its best to
+;;; work its way out.
+
+;;; The version of this program as described has a small problem. a
+;;; move in a net direction can produce gross credit assignment. for
+;;; example, if moving south will produce positive payoff, then, if in
+;;; a single move, one moves east,west and south, then both east and
+;;; west will be improved when they shouldn't
+
+;;; For further references see
+;;; http://rana.usc.edu:8376/~yuri/CS564/hw5.html
+
+
+
+
+
+
+
+
+
+
+
+;;;_* Provide
+
+(provide 'lm)
+
+
+
+
+
+
+
+;;;_* Require
+(require 'cl)
+
+
+
+
+
+
+;;;_* From Gomoku
+
+
+
+
+
+;;;_ +  THE BOARD.
+
+
+;; The board is a rectangular grid. We code empty squares with 0, X's with 1
+;; and O's with 6. The rectangle is recorded in a one dimensional vector
+;; containing padding squares (coded with -1). These squares allow us to
+;; detect when we are trying to move out of the board.	We denote a square by
+;; its (X,Y) coords, or by the INDEX corresponding to them in the vector.  The
+;; leftmost topmost square has coords (1,1) and index lm-board-width + 2.
+;; Similarly, vectors between squares may be given by two DX, DY coords or by
+;; one DEPL (the difference between indexes).
+
+(defvar lm-board-width nil
+  "Number of columns on the Lm board.")
+(defvar lm-board-height nil
+  "Number of lines on the Lm board.")
+
+(defvar lm-board nil
+  "Vector recording the actual state of the Lm board.")
+
+(defvar lm-vector-length nil
+  "Length of lm-board vector.")
+
+(defvar lm-draw-limit nil
+  ;; This is usually set to 70% of the number of squares.
+  "After how many moves will Emacs offer a draw?")
+
+(defun lm-xy-to-index (x y)
+  "Translate X, Y cartesian coords into the corresponding board index."
+  (+ (* y lm-board-width) x y))
+
+(defun lm-index-to-x (index)
+  "Return corresponding x-coord of board INDEX."
+  (% index (1+ lm-board-width)))
+
+(defun lm-index-to-y (index)
+  "Return corresponding y-coord of board INDEX."
+  (/ index (1+ lm-board-width)))
+
+(defun lm-init-board ()
+  "Create the lm-board vector and fill it with initial values."
+  (setq lm-board (make-vector lm-vector-length 0))
+  ;; Every square is 0 (i.e. empty) except padding squares:
+  (let ((i 0) (ii (1- lm-vector-length)))
+    (while (<= i lm-board-width)	; The squares in [0..width] and in
+      (aset lm-board i  -1)		;    [length - width - 1..length - 1]
+      (aset lm-board ii -1)		;    are padding squares.
+      (setq i  (1+ i)
+	    ii (1- ii))))
+  (let ((i 0))
+    (while (< i lm-vector-length)
+      (aset lm-board i -1)		; and also all k*(width+1)
+      (setq i (+ i lm-board-width 1)))))
+
+
+
+
+
+;;;_ +  LM MODE AND KEYMAP.
+
+(defvar lm-mode-hook nil
+  "If non-nil, its value is called on entry to Lm mode.")
+
+(defvar lm-mode-map nil
+  "Local keymap to use in Lm mode.")
+
+(if lm-mode-map nil
+  (setq lm-mode-map (make-sparse-keymap))
+
+  ;; Key bindings for cursor motion.
+  (define-key lm-mode-map "y" 'lm-move-nw)		; y
+  (define-key lm-mode-map "u" 'lm-move-ne)		; u
+  (define-key lm-mode-map "b" 'lm-move-sw)		; b
+  (define-key lm-mode-map "n" 'lm-move-se)		; n
+  (define-key lm-mode-map "h" 'backward-char)		; h
+  (define-key lm-mode-map "l" 'forward-char)		; l
+  (define-key lm-mode-map "j" 'lm-move-down)		; j
+  (define-key lm-mode-map "k" 'lm-move-up)		; k
+
+  (define-key lm-mode-map [kp-7] 'lm-move-nw)
+  (define-key lm-mode-map [kp-9] 'lm-move-ne)
+  (define-key lm-mode-map [kp-1] 'lm-move-sw)
+  (define-key lm-mode-map [kp-3] 'lm-move-se)
+  (define-key lm-mode-map [kp-4] 'backward-char)
+  (define-key lm-mode-map [kp-6] 'forward-char)
+  (define-key lm-mode-map [kp-2] 'lm-move-down)
+  (define-key lm-mode-map [kp-8] 'lm-move-up)
+
+  (define-key lm-mode-map "\C-n" 'lm-move-down)		; C-n
+  (define-key lm-mode-map "\C-p" 'lm-move-up)		; C-p
+
+  ;; Key bindings for entering Human moves.
+  (define-key lm-mode-map "X" 'lm-human-plays)		; X
+  (define-key lm-mode-map "x" 'lm-human-plays)		; x
+
+  (define-key lm-mode-map " " 'lm-start-robot)		; SPC
+  (define-key lm-mode-map [down-mouse-1] 'lm-start-robot)
+  (define-key lm-mode-map [drag-mouse-1] 'lm-click)
+  (define-key lm-mode-map [mouse-1] 'lm-click)
+  (define-key lm-mode-map [down-mouse-2] 'lm-click)
+  (define-key lm-mode-map [mouse-2] 'lm-mouse-play)
+  (define-key lm-mode-map [drag-mouse-2] 'lm-mouse-play)
+
+  (substitute-key-definition 'previous-line 'lm-move-up
+			     lm-mode-map (current-global-map))
+  (substitute-key-definition 'next-line 'lm-move-down
+			     lm-mode-map (current-global-map))
+  (substitute-key-definition 'beginning-of-line 'lm-beginning-of-line
+			     lm-mode-map (current-global-map))
+  (substitute-key-definition 'end-of-line 'lm-end-of-line
+			     lm-mode-map (current-global-map))
+  (substitute-key-definition 'undo 'lm-human-takes-back
+			     lm-mode-map (current-global-map))
+  (substitute-key-definition 'advertised-undo 'lm-human-takes-back
+			     lm-mode-map (current-global-map)))
+
+(defvar lm-emacs-won ()
+  "*For making font-lock use the winner's face for the line.")
+
+(defvar lm-font-lock-O-face
+  (if window-system
+      (list (facemenu-get-face 'fg:red) 'bold))
+  "*Face to use for Emacs' O.")
+
+(defvar lm-font-lock-X-face
+  (if window-system
+      (list (facemenu-get-face 'fg:green) 'bold))
+  "*Face to use for your X.")
+
+(defvar lm-font-lock-keywords
+  '(("O" . lm-font-lock-O-face)
+    ("X" . lm-font-lock-X-face)
+    ("[-|/\\]" 0 (if lm-emacs-won
+		     lm-font-lock-O-face
+		   lm-font-lock-X-face)))
+  "*Font lock rules for Lm.")
+
+(put 'lm-mode 'front-sticky
+     (put 'lm-mode 'rear-nonsticky '(intangible)))
+(put 'lm-mode 'intangible 1)
+
+(defun lm-mode ()
+  "Major mode for playing Lm against Emacs.
+You and Emacs play in turn by marking a free square.  You mark it with X
+and Emacs marks it with O.  The winner is the first to get five contiguous
+marks horizontally, vertically or in diagonal.
+
+You play by moving the cursor over the square you choose and hitting \\[lm-human-plays].
+
+Other useful commands:
+\\{lm-mode-map}
+Entry to this mode calls the value of `lm-mode-hook' if that value
+is non-nil.  One interesting value is `turn-on-font-lock'."
+  (interactive)
+  (setq major-mode 'lm-mode
+	mode-name "Lm")
+  (lm-display-statistics)
+  (use-local-map lm-mode-map)
+  (make-local-variable 'font-lock-defaults)
+  (setq font-lock-defaults '(lm-font-lock-keywords t))
+  (toggle-read-only t)
+  (run-hooks 'lm-mode-hook))
+
+
+
+
+
+;;;_ +  THE SCORE TABLE.
+
+
+;; Every (free) square has a score associated to it, recorded in the
+;; LM-SCORE-TABLE vector. The program always plays in the square having
+;; the highest score.
+
+(defvar lm-score-table nil
+  "Vector recording the actual score of the free squares.")
+
+
+;; The key point point about the algorithm is that, rather than considering
+;; the board as just a set of squares, we prefer to see it as a "space" of
+;; internested 5-tuples of contiguous squares (called qtuples).
+;;
+;; The aim of the program is to fill one qtuple with its O's while preventing
+;; you from filling another one with your X's. To that effect, it computes a
+;; score for every qtuple, with better qtuples having better scores. Of
+;; course, the score of a qtuple (taken in isolation) is just determined by
+;; its contents as a set, i.e. not considering the order of its elements. The
+;; highest score is given to the "OOOO" qtuples because playing in such a
+;; qtuple is winning the game. Just after this comes the "XXXX" qtuple because
+;; not playing in it is just loosing the game, and so on. Note that a
+;; "polluted" qtuple, i.e. one containing at least one X and at least one O,
+;; has score zero because there is no more any point in playing in it, from
+;; both an attacking and a defending point of view.
+;;
+;; Given the score of every qtuple, the score of a given free square on the
+;; board is just the sum of the scores of all the qtuples to which it belongs,
+;; because playing in that square is playing in all its containing qtuples at
+;; once. And it is that function which takes into account the internesting of
+;; the qtuples.
+;;
+;; This algorithm is rather simple but anyway it gives a not so dumb level of
+;; play. It easily extends to "n-dimensional Lm", where a win should not
+;; be obtained with as few as 5 contiguous marks: 6 or 7 (depending on n !)
+;; should be preferred.
+
+
+;; Here are the scores of the nine "non-polluted" configurations.  Tuning
+;; these values will change (hopefully improve) the strength of the program
+;; and may change its style (rather aggressive here).
+
+(defconst nil-score	  7  "Score of an empty qtuple.")
+(defconst Xscore	 15  "Score of a qtuple containing one X.")
+(defconst XXscore	400  "Score of a qtuple containing two X's.")
+(defconst XXXscore     1800  "Score of a qtuple containing three X's.")
+(defconst XXXXscore  100000  "Score of a qtuple containing four X's.")
+(defconst Oscore	 35  "Score of a qtuple containing one O.")
+(defconst OOscore	800  "Score of a qtuple containing two O's.")
+(defconst OOOscore    15000  "Score of a qtuple containing three O's.")
+(defconst OOOOscore  800000  "Score of a qtuple containing four O's.")
+
+;; These values are not just random: if, given the following situation:
+;;
+;;			  . . . . . . . O .
+;;			  . X X a . . . X .
+;;			  . . . X . . . X .
+;;			  . . . X . . . X .
+;;			  . . . . . . . b .
+;;
+;; you want Emacs to play in "a" and not in "b", then the parameters must
+;; satisfy the inequality:
+;;
+;;		   6 * XXscore > XXXscore + XXscore
+;;
+;; because "a" mainly belongs to six "XX" qtuples (the others are less
+;; important) while "b" belongs to one "XXX" and one "XX" qtuples.  Other
+;; conditions are required to obtain sensible moves, but the previous example
+;; should illustrate the point. If you manage to improve on these values,
+;; please send me a note. Thanks.
+
+
+;; As we chose values 0, 1 and 6 to denote empty, X and O squares, the
+;; contents of a qtuple are uniquely determined by the sum of its elements and
+;; we just have to set up a translation table.
+
+(defconst lm-score-trans-table
+  (vector nil-score Xscore XXscore XXXscore XXXXscore 0
+	  Oscore    0	   0	   0	    0	      0
+	  OOscore   0	   0	   0	    0	      0
+	  OOOscore  0	   0	   0	    0	      0
+	  OOOOscore 0	   0	   0	    0	      0
+	  0)
+  "Vector associating qtuple contents to their score.")
+
+
+;; If you do not modify drastically the previous constants, the only way for a
+;; square to have a score higher than OOOOscore is to belong to a "OOOO"
+;; qtuple, thus to be a winning move. Similarly, the only way for a square to
+;; have a score between XXXXscore and OOOOscore is to belong to a "XXXX"
+;; qtuple. We may use these considerations to detect when a given move is
+;; winning or loosing.
+
+(defconst lm-winning-threshold OOOOscore
+  "Threshold score beyond which an Emacs move is winning.")
+
+(defconst lm-loosing-threshold XXXXscore
+  "Threshold score beyond which a human move is winning.")
+
+
+(defun lm-strongest-square ()
+  "Compute index of free square with highest score, or nil if none."
+  ;; We just have to loop other all squares. However there are two problems:
+  ;; 1/ The SCORE-TABLE only gives correct scores to free squares. To speed
+  ;;	up future searches, we set the score of padding or occupied squares
+  ;;	to -1 whenever we meet them.
+  ;; 2/ We want to choose randomly between equally good moves.
+  (let ((score-max 0)
+	(count	   0)			; Number of equally good moves
+	(square	   (lm-xy-to-index 1 1)) ; First square
+	(end	   (lm-xy-to-index lm-board-width lm-board-height))
+	best-square score)
+    (while (<= square end)
+      (cond
+       ;; If score is lower (i.e. most of the time), skip to next:
+       ((< (aref lm-score-table square) score-max))
+       ;; If score is better, beware of non free squares:
+       ((> (setq score (aref lm-score-table square)) score-max)
+	(if (zerop (aref lm-board square)) ; is it free ?
+	    (setq count 1		       ; yes: take it !
+		  best-square square
+		  score-max   score)
+	    (aset lm-score-table square -1))) ; no: kill it !
+       ;; If score is equally good, choose randomly. But first check freeness:
+       ((not (zerop (aref lm-board square)))
+	(aset lm-score-table square -1))
+       ((zerop (random (setq count (1+ count))))
+	(setq best-square square
+	      score-max	  score)))
+      (setq square (1+ square)))	; try next square
+    best-square))
+
+;;;_  -  INITIALIZING THE SCORE TABLE.
+
+;; At initialization the board is empty so that every qtuple amounts for
+;; nil-score. Therefore, the score of any square is nil-score times the number
+;; of qtuples that pass through it. This number is 3 in a corner and 20 if you
+;; are sufficiently far from the sides. As computing the number is time
+;; consuming, we initialize every square with 20*nil-score and then only
+;; consider squares at less than 5 squares from one side. We speed this up by
+;; taking symmetry into account.
+;; Also, as it is likely that successive games will be played on a board with
+;; same size, it is a good idea to save the initial SCORE-TABLE configuration.
+
+(defvar lm-saved-score-table nil
+  "Recorded initial value of previous score table.")
+
+(defvar lm-saved-board-width nil
+  "Recorded value of previous board width.")
+
+(defvar lm-saved-board-height nil
+  "Recorded value of previous board height.")
+
+
+(defun lm-init-score-table ()
+  "Create the score table vector and fill it with initial values."
+  (if (and lm-saved-score-table	; Has it been stored last time ?
+	   (= lm-board-width  lm-saved-board-width)
+	   (= lm-board-height lm-saved-board-height))
+      (setq lm-score-table (copy-sequence lm-saved-score-table))
+      ;; No, compute it:
+      (setq lm-score-table
+	    (make-vector lm-vector-length (* 20 nil-score)))
+      (let (i j maxi maxj maxi2 maxj2)
+	(setq maxi  (/ (1+ lm-board-width) 2)
+	      maxj  (/ (1+ lm-board-height) 2)
+	      maxi2 (min 4 maxi)
+	      maxj2 (min 4 maxj))
+	;; We took symmetry into account and could use it more if the board
+	;; would have been square and not rectangular !
+	;; In our case we deal with all (i,j) in the set [1..maxi2]*[1..maxj] U
+	;; [maxi2+1..maxi]*[1..maxj2]. Maxi2 and maxj2 are used because the
+	;; board may well be less than 8 by 8 !
+	(setq i 1)
+	(while (<= i maxi2)
+	  (setq j 1)
+	  (while (<= j maxj)
+	    (lm-init-square-score i j)
+	    (setq j (1+ j)))
+	  (setq i (1+ i)))
+	(while (<= i maxi)
+	  (setq j 1)
+	  (while (<= j maxj2)
+	    (lm-init-square-score i j)
+	    (setq j (1+ j)))
+	  (setq i (1+ i))))
+      (setq lm-saved-score-table  (copy-sequence lm-score-table)
+	    lm-saved-board-width  lm-board-width
+	    lm-saved-board-height lm-board-height)))
+
+(defun lm-nb-qtuples (i j)
+  "Return the number of qtuples containing square I,J."
+  ;; This function is complicated because we have to deal
+  ;; with ugly cases like 3 by 6 boards, but it works.
+  ;; If you have a simpler (and correct) solution, send it to me. Thanks !
+  (let ((left  (min 4 (1- i)))
+	(right (min 4 (- lm-board-width i)))
+	(up    (min 4 (1- j)))
+	(down  (min 4 (- lm-board-height j))))
+    (+ -12
+       (min (max (+ left right) 3) 8)
+       (min (max (+ up down) 3) 8)
+       (min (max (+ (min left up) (min right down)) 3) 8)
+       (min (max (+ (min right up) (min left down)) 3) 8))))
+
+(defun lm-init-square-score (i j)
+  "Give initial score to square I,J and to its mirror images."
+  (let ((ii (1+ (- lm-board-width i)))
+	(jj (1+ (- lm-board-height j)))
+	(sc (* (lm-nb-qtuples i j) (aref lm-score-trans-table 0))))
+    (aset lm-score-table (lm-xy-to-index i  j)	sc)
+    (aset lm-score-table (lm-xy-to-index ii j)	sc)
+    (aset lm-score-table (lm-xy-to-index i  jj) sc)
+    (aset lm-score-table (lm-xy-to-index ii jj) sc)))
+;;;_  - MAINTAINING THE SCORE TABLE.
+
+
+;; We do not provide functions for computing the SCORE-TABLE given the
+;; contents of the BOARD. This would involve heavy nested loops, with time
+;; proportional to the size of the board. It is better to update the
+;; SCORE-TABLE after each move. Updating needs not modify more than 36
+;; squares: it is done in constant time.
+
+(defun lm-update-score-table (square dval)
+  "Update score table after SQUARE received a DVAL increment."
+  ;; The board has already been updated when this function is called.
+  ;; Updating scores is done by looking for qtuples boundaries in all four
+  ;; directions and then calling update-score-in-direction.
+  ;; Finally all squares received the right increment, and then are up to
+  ;; date, except possibly for SQUARE itself if we are taking a move back for
+  ;; its score had been set to -1 at the time.
+  (let* ((x    (lm-index-to-x square))
+	 (y    (lm-index-to-y square))
+	 (imin (max -4 (- 1 x)))
+	 (jmin (max -4 (- 1 y)))
+	 (imax (min 0 (- lm-board-width x 4)))
+	 (jmax (min 0 (- lm-board-height y 4))))
+    (lm-update-score-in-direction imin imax
+				      square 1 0 dval)
+    (lm-update-score-in-direction jmin jmax
+				      square 0 1 dval)
+    (lm-update-score-in-direction (max imin jmin) (min imax jmax)
+				      square 1 1 dval)
+    (lm-update-score-in-direction (max (- 1 y) -4
+					   (- x lm-board-width))
+				      (min 0 (- x 5)
+					   (- lm-board-height y 4))
+				      square -1 1 dval)))
+
+(defun lm-update-score-in-direction (left right square dx dy dval)
+  "Update scores for all squares in the qtuples starting between the LEFTth
+square and the RIGHTth after SQUARE, along the DX, DY direction, considering
+that DVAL has been added on SQUARE."
+  ;; We always have LEFT <= 0, RIGHT <= 0 and DEPL > 0 but we may very well
+  ;; have LEFT > RIGHT, indicating that no qtuple contains SQUARE along that
+  ;; DX,DY direction.
+  (cond
+   ((> left right))			; Quit
+   (t					; Else ..
+    (let (depl square0 square1 square2 count delta)
+      (setq depl    (lm-xy-to-index dx dy)
+	    square0 (+ square (* left depl))
+	    square1 (+ square (* right depl))
+	    square2 (+ square0 (* 4 depl)))
+      ;; Compute the contents of the first qtuple:
+      (setq square square0
+	    count  0)
+      (while (<= square square2)
+	(setq count  (+ count (aref lm-board square))
+	      square (+ square depl)))
+      (while (<= square0 square1)
+	;; Update the squares of the qtuple beginning in SQUARE0 and ending
+	;; in SQUARE2.
+	(setq delta (- (aref lm-score-trans-table count)
+		       (aref lm-score-trans-table (- count dval))))
+	(cond ((not (zerop delta))	; or else nothing to update
+	       (setq square square0)
+	       (while (<= square square2)
+		 (if (zerop (aref lm-board square)) ; only for free squares
+		     (aset lm-score-table square
+			   (+ (aref lm-score-table square) delta)))
+		 (setq square (+ square depl)))))
+	;; Then shift the qtuple one square along DEPL, this only requires
+	;; modifying SQUARE0 and SQUARE2.
+	(setq square2 (+ square2 depl)
+	      count   (+ count (- (aref lm-board square0))
+			 (aref lm-board square2))
+	      square0 (+ square0 depl)))))))
+
+;;;
+;;; GAME CONTROL.
+;;;
+
+;; Several variables are used to monitor a game, including a GAME-HISTORY (the
+;; list of all (SQUARE . PREVSCORE) played) that allows to take moves back
+;; (anti-updating the score table) and to compute the table from scratch in
+;; case of an interruption.
+
+(defvar lm-game-in-progress nil
+  "Non-nil if a game is in progress.")
+
+(defvar lm-game-history nil
+  "A record of all moves that have been played during current game.")
+
+(defvar lm-number-of-moves nil
+  "Number of moves already played in current game.")
+
+(defvar lm-number-of-human-moves nil
+  "Number of moves already played by human in current game.")
+
+(defvar lm-emacs-played-first nil
+  "Non-nil if Emacs played first.")
+
+(defvar lm-human-took-back nil
+  "Non-nil if Human took back a move during the game.")
+
+(defvar lm-human-refused-draw nil
+  "Non-nil if Human refused Emacs offer of a draw.")
+
+(defvar lm-emacs-is-computing nil
+  ;; This is used to detect interruptions. Hopefully, it should not be needed.
+  "Non-nil if Emacs is in the middle of a computation.")
+
+
+(defun lm-start-game (n m)
+  "Initialize a new game on an N by M board."
+  (setq lm-emacs-is-computing t)	; Raise flag
+  (setq lm-game-in-progress t)
+  (setq lm-board-width   n
+	lm-board-height  m
+	lm-vector-length (1+ (* (+ m 2) (1+ n)))
+	lm-draw-limit    (/ (* 7 n m) 10))
+  (setq lm-emacs-won	     nil
+	lm-game-history	     nil
+	lm-number-of-moves	     0
+	lm-number-of-human-moves 0
+	lm-emacs-played-first    nil
+	lm-human-took-back	     nil
+	lm-human-refused-draw    nil)
+  (lm-init-display n m)		; Display first: the rest takes time
+  (lm-init-score-table)		; INIT-BOARD requires that the score
+  (lm-init-board)			;   table be already created.
+  (setq lm-emacs-is-computing nil))
+
+(defun lm-play-move (square val &optional dont-update-score)
+  "Go to SQUARE, play VAL and update everything."
+  (setq lm-emacs-is-computing t)	; Raise flag
+  (cond ((= 1 val)			; a Human move
+	 (setq lm-number-of-human-moves (1+ lm-number-of-human-moves)))
+	((zerop lm-number-of-moves)	; an Emacs move. Is it first ?
+	 (setq lm-emacs-played-first t)))
+  (setq lm-game-history
+	(cons (cons square (aref lm-score-table square))
+	      lm-game-history)
+	lm-number-of-moves (1+ lm-number-of-moves))
+  (lm-plot-square square val)
+  (aset lm-board square val)	; *BEFORE* UPDATE-SCORE !
+  (if dont-update-score nil
+      (lm-update-score-table square val) ; previous val was 0: dval = val
+      (aset lm-score-table square -1))
+  (setq lm-emacs-is-computing nil))
+
+(defun lm-take-back ()
+  "Take back last move and update everything."
+  (setq lm-emacs-is-computing t)
+  (let* ((last-move (car lm-game-history))
+	 (square (car last-move))
+	 (oldval (aref lm-board square)))
+    (if (= 1 oldval)
+	(setq lm-number-of-human-moves (1- lm-number-of-human-moves)))
+    (setq lm-game-history	 (cdr lm-game-history)
+	  lm-number-of-moves (1- lm-number-of-moves))
+    (lm-plot-square square 0)
+    (aset lm-board square 0)	; *BEFORE* UPDATE-SCORE !
+    (lm-update-score-table square (- oldval))
+    (aset lm-score-table square (cdr last-move)))
+  (setq lm-emacs-is-computing nil))
+
+
+
+;;;_ +  SESSION CONTROL.
+
+
+(defvar lm-number-of-emacs-wins 0
+  "Number of games Emacs won in this session.")
+
+(defvar lm-number-of-human-wins 0
+  "Number of games you won in this session.")
+
+(defvar lm-number-of-draws 0
+  "Number of games already drawn in this session.")
+
+
+(defun lm-terminate-game (result)
+  "Terminate the current game with RESULT."
+  (message
+   (cond
+    ((eq result 'emacs-won)
+     (setq lm-number-of-emacs-wins (1+ lm-number-of-emacs-wins))
+     (cond ((< lm-number-of-moves 20)
+	    "This was a REALLY QUICK win.")
+	   (lm-human-refused-draw
+	    "I won... Too bad you refused my offer of a draw !")
+	   (lm-human-took-back
+	    "I won... Taking moves back will not help you !")
+	   ((not lm-emacs-played-first)
+	    "I won... Playing first did not help you much !")
+	   ((and (zerop lm-number-of-human-wins)
+		 (zerop lm-number-of-draws)
+		 (> lm-number-of-emacs-wins 1))
+	    "I'm becoming tired of winning...")
+	   ("I won.")))
+    ((eq result 'human-won)
+     (setq lm-number-of-human-wins (1+ lm-number-of-human-wins))
+     (concat "OK, you won this one."
+	     (cond
+	      (lm-human-took-back
+	       "  I, for one, never take my moves back...")
+	      (lm-emacs-played-first
+	       ".. so what ?")
+	      ("  Now, let me play first just once."))))
+    ((eq result 'human-resigned)
+     (setq lm-number-of-emacs-wins (1+ lm-number-of-emacs-wins))
+     "So you resign.  That's just one more win for me.")
+    ((eq result 'nobody-won)
+     (setq lm-number-of-draws (1+ lm-number-of-draws))
+     (concat "This is a draw.  "
+	     (cond
+	      (lm-human-took-back
+	       "I, for one, never take my moves back...")
+	      (lm-emacs-played-first
+	       "Just chance, I guess.")
+	      ("Now, let me play first just once."))))
+    ((eq result 'draw-agreed)
+     (setq lm-number-of-draws (1+ lm-number-of-draws))
+     (concat "Draw agreed.  "
+	     (cond
+	      (lm-human-took-back
+	       "I, for one, never take my moves back...")
+	      (lm-emacs-played-first
+	       "You were lucky.")
+	      ("Now, let me play first just once."))))
+    ((eq result 'crash-game)
+     "Sorry, I have been interrupted and cannot resume that game...")))
+  (lm-display-statistics)
+  ;;(ding)
+  (setq lm-game-in-progress nil))
+
+(defun lm-crash-game ()
+  "What to do when Emacs detects it has been interrupted."
+  (setq lm-emacs-is-computing nil)
+  (lm-terminate-game 'crash-game)
+  (sit-for 4)				; Let's see the message
+  (lm-prompt-for-other-game))
+
+
+
+
+
+;;;_ +  INTERACTIVE COMMANDS.
+
+
+
+(defun lm-emacs-plays ()
+  "Compute Emacs next move and play it."
+  (interactive)
+  (lm-switch-to-window)
+  (cond
+   (lm-emacs-is-computing
+    (lm-crash-game))
+   ((not lm-game-in-progress)
+    (lm-prompt-for-other-game))
+   (t
+    (message "Let me think...")
+    (let (square score)
+      (setq square (lm-strongest-square))
+      (cond ((null square)
+	     (lm-terminate-game 'nobody-won))
+	    (t
+	     (setq score (aref lm-score-table square))
+	     (lm-play-move square 6)
+	     (cond ((>= score lm-winning-threshold)
+		    (setq lm-emacs-won t) ; for font-lock
+		    (lm-find-filled-qtuple square 6)
+		    (lm-terminate-game 'emacs-won))
+		   ((zerop score)
+		    (lm-terminate-game 'nobody-won))
+		   ((and (> lm-number-of-moves lm-draw-limit)
+			 (not lm-human-refused-draw)
+			 (lm-offer-a-draw))
+		    (lm-terminate-game 'draw-agreed))
+		   (t
+		    (lm-prompt-for-move)))))))))
+
+;; For small square dimensions this is approximate, since though measured in
+;; pixels, event's (X . Y) is a character's top-left corner.
+(defun lm-click (click)
+  "Position at the square where you click."
+  (interactive "e")
+  (and (windowp (posn-window (setq click (event-end click))))
+       (numberp (posn-point click))
+       (select-window (posn-window click))
+       (setq click (posn-col-row click))
+       (lm-goto-xy
+	(min (max (/ (+ (- (car click)
+			   lm-x-offset
+			   1)
+			(window-hscroll)
+			lm-square-width
+			(% lm-square-width 2)
+			(/ lm-square-width 2))
+		     lm-square-width)
+		  1)
+	     lm-board-width)
+	(min (max (/ (+ (- (cdr click)
+			   lm-y-offset
+			   1)
+			(let ((inhibit-point-motion-hooks t))
+			  (count-lines 1 (window-start)))
+			lm-square-height
+			(% lm-square-height 2)
+			(/ lm-square-height 2))
+		     lm-square-height)
+		  1)
+	     lm-board-height))))
+  
+(defun lm-mouse-play (click)
+  "Play at the square where you click."
+  (interactive "e")
+  (if (lm-click click)
+      (lm-human-plays)))
+
+(defun lm-human-plays ()
+  "Signal to the Lm program that you have played.
+You must have put the cursor on the square where you want to play.
+If the game is finished, this command requests for another game."
+  (interactive)
+  (lm-switch-to-window)
+  (cond
+   (lm-emacs-is-computing
+    (lm-crash-game))
+   ((not lm-game-in-progress)
+    (lm-prompt-for-other-game))
+   (t
+    (let (square score)
+      (setq square (lm-point-square))
+      (cond ((null square)
+	     (error "Your point is not on a square. Retry !"))
+	    ((not (zerop (aref lm-board square)))
+	     (error "Your point is not on a free square. Retry !"))
+	    (t
+	     (setq score (aref lm-score-table square))
+	     (lm-play-move square 1)
+	     (cond ((and (>= score lm-loosing-threshold)
+			 ;; Just testing SCORE > THRESHOLD is not enough for
+			 ;; detecting wins, it just gives an indication that
+			 ;; we confirm with LM-FIND-FILLED-QTUPLE.
+			 (lm-find-filled-qtuple square 1))
+		    (lm-terminate-game 'human-won))
+		   (t
+		    (lm-emacs-plays)))))))))
+
+(defun lm-human-takes-back ()
+  "Signal to the Lm program that you wish to take back your last move."
+  (interactive)
+  (lm-switch-to-window)
+  (cond
+   (lm-emacs-is-computing
+    (lm-crash-game))
+   ((not lm-game-in-progress)
+    (message "Too late for taking back...")
+    (sit-for 4)
+    (lm-prompt-for-other-game))
+   ((zerop lm-number-of-human-moves)
+    (message "You have not played yet... Your move ?"))
+   (t
+    (message "One moment, please...")
+    ;; It is possible for the user to let Emacs play several consecutive
+    ;; moves, so that the best way to know when to stop taking back moves is
+    ;; to count the number of human moves:
+    (setq lm-human-took-back t)
+    (let ((number lm-number-of-human-moves))
+      (while (= number lm-number-of-human-moves)
+	(lm-take-back)))
+    (lm-prompt-for-move))))
+
+(defun lm-human-resigns ()
+  "Signal to the Lm program that you may want to resign."
+  (interactive)
+  (lm-switch-to-window)
+  (cond
+   (lm-emacs-is-computing
+    (lm-crash-game))
+   ((not lm-game-in-progress)
+    (message "There is no game in progress"))
+   ((y-or-n-p "You mean, you resign ")
+    (lm-terminate-game 'human-resigned))
+   ((y-or-n-p "You mean, we continue ")
+    (lm-prompt-for-move))
+   (t
+    (lm-terminate-game 'human-resigned)))) ; OK. Accept it
+
+
+
+;;;_ + PROMPTING THE HUMAN PLAYER.
+
+(defun lm-prompt-for-move ()
+  "Display a message asking for Human's move."
+  (message (if (zerop lm-number-of-human-moves)
+	       "Your move ? (move to a free square and hit X, RET ...)"
+	       "Your move ?"))
+  ;; This may seem silly, but if one omits the following line (or a similar
+  ;; one), the cursor may very well go to some place where POINT is not.
+  (save-excursion (set-buffer (other-buffer))))
+
+(defun lm-prompt-for-other-game ()
+  "Ask for another game, and start it."
+  (if (y-or-n-p "Another game ")
+      (lm lm-board-width lm-board-height)
+    (message "Chicken !")))
+
+(defun lm-offer-a-draw ()
+  "Offer a draw and return T if Human accepted it."
+  (or (y-or-n-p "I offer you a draw. Do you accept it ")
+      (not (setq lm-human-refused-draw t))))
+
+
+
+;;;_ +  DISPLAYING THE BOARD.
+
+;; You may change these values if you have a small screen or if the squares
+;; look rectangular, but spacings SHOULD be at least 2 (MUST BE at least 1).
+
+(defconst lm-square-width 2
+  "*Horizontal spacing between squares on the Lm board.")
+
+(defconst lm-square-height 1
+  "*Vertical spacing between squares on the Lm board.")
+
+(defconst lm-x-offset 3
+  "*Number of columns between the Lm board and the side of the window.")
+
+(defconst lm-y-offset 1
+  "*Number of lines between the Lm board and the top of the window.")
+
+
+(defun lm-max-width ()
+  "Largest possible board width for the current window."
+  (1+ (/ (- (window-width (selected-window))
+	    lm-x-offset lm-x-offset 1)
+	 lm-square-width)))
+
+(defun lm-max-height ()
+  "Largest possible board height for the current window."
+  (1+ (/ (- (window-height (selected-window))
+	    lm-y-offset lm-y-offset 2)
+	 ;; 2 instead of 1 because WINDOW-HEIGHT includes the mode line !
+	 lm-square-height)))
+
+(defun lm-point-y ()
+  "Return the board row where point is."
+  (let ((inhibit-point-motion-hooks t))
+    (1+ (/ (- (count-lines 1 (point)) lm-y-offset (if (bolp) 0 1))
+	   lm-square-height))))
+(defun my-lm-point-y ()
+  (interactive)
+  "Return the board row where point is."
+  (let ((inhibit-point-motion-hooks t))
+    (message (format "%S"
+	      (1+ (/ (- (count-lines 1 (point)) lm-y-offset (if (bolp) 0 1))
+		     lm-square-height))))))
+
+(defun lm-point-square ()
+  "Return the index of the square point is on."
+  (let ((inhibit-point-motion-hooks t))
+    (lm-xy-to-index (1+ (/ (- (current-column) lm-x-offset)
+			       lm-square-width))
+			(lm-point-y))))
+
+(defun lm-goto-square (index)
+  "Move point to square number INDEX."
+  (lm-goto-xy (lm-index-to-x index) (lm-index-to-y index)))
+
+(defun lm-goto-xy (x y)
+  "Move point to square at X, Y coords."
+  (let ((inhibit-point-motion-hooks t))
+    (goto-line (+ 1 lm-y-offset (* lm-square-height (1- y)))))
+  (move-to-column (+ lm-x-offset (* lm-square-width (1- x)))))
+
+(defun lm-plot-square (square value)
+  "Draw 'X', 'O' or '.' on SQUARE depending on VALUE, leave point there."
+  (or (= value 1)
+      (lm-goto-square square))
+  (let ((inhibit-read-only t)
+	(inhibit-point-motion-hooks t))
+    (insert-and-inherit (cond ((= value 1) ?.)
+			      ((= value 2) ?N)
+			      ((= value 3) ?S)
+			      ((= value 4) ?E)
+			      ((= value 5) ?W)
+			      ((= value 6) ?^)))
+
+    (and window-system
+	 (zerop value)
+	 (put-text-property (1- (point)) (point) 'mouse-face 'highlight))
+    (delete-char 1)
+    (backward-char 1))
+  (sit-for 0))	; Display NOW
+
+(defun lm-init-display (n m)
+  "Display an N by M Lm board."
+  (buffer-disable-undo (current-buffer))
+  (let ((inhibit-read-only t)
+	(point 1) opoint
+	(intangible t)
+	(i m) j x)
+    ;; Try to minimize number of chars (because of text properties)
+    (setq tab-width
+	  (if (zerop (% lm-x-offset lm-square-width))
+	      lm-square-width
+	    (max (/ (+ (% lm-x-offset lm-square-width)
+		       lm-square-width 1) 2) 2)))
+    (erase-buffer)
+    (newline lm-y-offset)
+    (while (progn
+	     (setq j n
+		   x (- lm-x-offset lm-square-width))
+	     (while (>= (setq j (1- j)) 0)
+	       (insert-char ?\t (/ (- (setq x (+ x lm-square-width))
+				      (current-column))
+				   tab-width))
+	       (insert-char ?  (- x (current-column)))
+	       (if (setq intangible (not intangible))
+		   (put-text-property point (point) 'intangible 2))
+	       (and (zerop j)
+		    (= i (- m 2))
+		    (progn
+		      (while (>= i 3)
+			(append-to-buffer (current-buffer) opoint (point))
+			(setq i (- i 2)))
+		      (goto-char (point-max))))
+	       (setq point (point))
+	       (insert ?=)
+	       (if window-system
+		   (put-text-property point (point)
+				      'mouse-face 'highlight)))
+	     (> (setq i (1- i)) 0))
+      (if (= i (1- m))
+	  (setq opoint point))
+      (insert-char ?\n lm-square-height))
+    (or (eq (char-after 1) ?.)
+	(put-text-property 1 2 'point-entered
+			   (lambda (x x) (if (bobp) (forward-char)))))
+    (or intangible
+	(put-text-property point (point) 'intangible 2))
+    (put-text-property point (point) 'point-entered
+		       (lambda (x x) (if (eobp) (backward-char))))
+    (put-text-property (point-min) (point) 'category 'lm-mode))
+  (lm-goto-xy (/ (1+ n) 2) (/ (1+ m) 2)) ; center of the board
+  (sit-for 0))				; Display NOW
+
+(defun lm-display-statistics ()
+  "Obnoxiously display some statistics about previous games in mode line."
+  ;; We store this string in the mode-line-process local variable.
+  ;; This is certainly not the cleanest way out ...
+  (setq mode-line-process
+	(format ": Won %d, lost %d%s"
+		lm-number-of-human-wins
+		lm-number-of-emacs-wins
+		(if (zerop lm-number-of-draws)
+		    ""
+		  (format ", drew %d" lm-number-of-draws))))
+  (force-mode-line-update))
+
+(defun lm-switch-to-window ()
+  "Find or create the Lm buffer, and display it."
+  (interactive)
+  (let ((buff (get-buffer "*Lm*")))
+    (if buff				; Buffer exists:
+	(switch-to-buffer buff)		;   no problem.
+      (if lm-game-in-progress
+	  (lm-crash-game))		;   buffer has been killed or something
+      (switch-to-buffer "*Lm*")	; Anyway, start anew.
+      (lm-mode))))
+
+
+
+;;;_ + CROSSING WINNING QTUPLES.
+
+;; When someone succeeds in filling a qtuple, we draw a line over the five
+;; corresponding squares. One problem is that the program does not know which
+;; squares ! It only knows the square where the last move has been played and
+;; who won. The solution is to scan the board along all four directions.
+
+(defun lm-find-filled-qtuple (square value)
+  "Return T if SQUARE belongs to a qtuple filled with VALUEs."
+  (or (lm-check-filled-qtuple square value 1 0)
+      (lm-check-filled-qtuple square value 0 1)
+      (lm-check-filled-qtuple square value 1 1)
+      (lm-check-filled-qtuple square value -1 1)))
+
+(defun lm-check-filled-qtuple (square value dx dy)
+  "Return T if SQUARE belongs to a qtuple filled  with VALUEs along DX, DY."
+  (let ((a 0) (b 0)
+	(left square) (right square)
+	(depl (lm-xy-to-index dx dy)))
+    (while (and (> a -4)		; stretch tuple left
+		(= value (aref lm-board (setq left (- left depl)))))
+      (setq a (1- a)))
+    (while (and (< b (+ a 4))		; stretch tuple right
+		(= value (aref lm-board (setq right (+ right depl)))))
+      (setq b (1+ b)))
+    (cond ((= b (+ a 4))		; tuple length = 5 ?
+	   (lm-cross-qtuple (+ square (* a depl)) (+ square (* b depl))
+				dx dy)
+	   t))))
+
+(defun lm-cross-qtuple (square1 square2 dx dy)
+  "Cross every square between SQUARE1 and SQUARE2 in the DX, DY direction."
+  (save-excursion			; Not moving point from last square
+    (let ((depl (lm-xy-to-index dx dy))
+	  (inhibit-read-only t)
+	  (inhibit-point-motion-hooks t))
+      ;; WARNING: this function assumes DEPL > 0 and SQUARE2 > SQUARE1
+      (while (/= square1 square2)
+	(lm-goto-square square1)
+	(setq square1 (+ square1 depl))
+	(cond
+	  ((= dy 0)			; Horizontal
+	   (forward-char 1)
+	   (insert-char ?- (1- lm-square-width) t)
+	   (delete-region (point) (progn
+				    (skip-chars-forward " \t")
+				    (point))))
+	  ((= dx 0)			; Vertical
+	   (let ((n 1)
+		 (column (current-column)))
+	     (while (< n lm-square-height)
+	       (setq n (1+ n))
+	       (forward-line 1)
+	       (indent-to column)
+	       (insert-and-inherit ?|))))
+	  ((= dx -1)			; 1st Diagonal
+	   (indent-to (prog1 (- (current-column) (/ lm-square-width 2))
+			(forward-line (/ lm-square-height 2))))
+	   (insert-and-inherit ?/))
+	  (t				; 2nd Diagonal
+	   (indent-to (prog1 (+ (current-column) (/ lm-square-width 2))
+			(forward-line (/ lm-square-height 2))))
+	   (insert-and-inherit ?\\))))))
+  (sit-for 0))				; Display NOW
+
+
+
+;;;_ + CURSOR MOTION.
+
+;; previous-line and next-line don't work right with intangible newlines
+(defun lm-move-down ()
+  "Move point down one row on the Lm board."
+  (interactive)
+  (if (< (lm-point-y) lm-board-height)
+      (next-line 1)));;; lm-square-height)))
+
+(defun lm-move-up ()
+  "Move point up one row on the Lm board."
+  (interactive)
+  (if (> (lm-point-y) 1)
+      (previous-line lm-square-height)))
+
+(defun lm-move-ne ()
+  "Move point North East on the Lm board."
+  (interactive)
+  (lm-move-up)
+  (forward-char))
+
+(defun lm-move-se ()
+  "Move point South East on the Lm board."
+  (interactive)
+  (lm-move-down)
+  (forward-char))
+
+(defun lm-move-nw ()
+  "Move point North West on the Lm board."
+  (interactive)
+  (lm-move-up)
+  (backward-char))
+
+(defun lm-move-sw ()
+  "Move point South West on the Lm board."
+  (interactive)
+  (lm-move-down)
+  (backward-char))
+
+(defun lm-beginning-of-line ()
+  "Move point to first square on the Lm board row."
+  (interactive)
+  (move-to-column lm-x-offset))
+
+(defun lm-end-of-line ()
+  "Move point to last square on the Lm board row."
+  (interactive)
+  (move-to-column (+ lm-x-offset
+		     (* lm-square-width (1- lm-board-width)))))
+
+(provide 'lm)
+
+  
+(defun lm-xy-to-index (x y)
+  "Translate X, Y cartesian coords into the corresponding board index."
+  (+ (* y lm-board-width) x y))
+
+(defun lm-index-to-x (index)
+  "Return corresponding x-coord of board INDEX."
+  (% index (1+ lm-board-width)))
+
+(defun lm-index-to-y (index)
+  "Return corresponding y-coord of board INDEX."
+  (/ index (1+ lm-board-width)))
+
+
+
+
+
+
+
+
+
+;;;_* Terry's mods to create lm.el
+
+
+
+
+
+;;;_ + Debugging things
+(setq debug-on-error t)
+;;;(setq lm-debug nil)
+(setq lm-debug t)
+
+(defun lm-maybe-debug ()
+
+    (if lm-debug
+	(progn (lm-print-wts) (lm-blackbox) (lm-print-y,s,noise)
+	(lm-print-smell))))
+
+;;;_  - Printing various things
+(defun lm-print-distance-int (direction)
+  (interactive)
+  (insert (format "%S %S " direction  (get direction 'distance))))
+
+
+(defun lm-print-distance ()
+  (insert (format "tree: %S \n" (calc-distance-of-robot-from 'lm-tree)))
+  (mapc 'lm-print-distance-int lm-directions))
+
+
+;;(setq direction 'lm-n)
+;;(get 'lm-n 'lm-s)
+(defun lm-nslify-wts-int (direction)
+  (mapcar '(lambda (target-direction)
+	     (get direction target-direction))
+	  lm-directions))
+
+
+(defun lm-nslify-wts ()
+  (interactive)
+  (let ((l (apply 'append (mapcar 'lm-nslify-wts-int lm-directions))))
+    (insert (format "set data_value WTS \n %s \n" l))
+    (insert (format "/* max: %S min: %S */"
+		  (eval (cons 'max l)) (eval (cons 'min l))))))
+
+(defun lm-print-wts-int (direction)
+  (mapc '(lambda (target-direction)
+	     (insert (format "%S %S %S "
+			      direction
+			      target-direction
+			     (get direction target-direction))))
+	  lm-directions)
+  (insert "\n"))
+
+(defun lm-print-wts ()
+  (interactive)
+  (save-excursion
+    (set-buffer "*lm-wts*")
+    (insert "==============================\n")
+    (mapc 'lm-print-wts-int lm-directions)))
+
+(defun lm-print-moves (moves)
+  (interactive)
+  (save-excursion
+    (set-buffer "*lm-moves*")
+    (insert (format "%S\n" moves))))
+
+
+(defun lm-print-y,s,noise-int (direction)
+  (insert (format "%S:lm-y %S, s %S, noise %S \n"
+		    (symbol-name direction)
+		    (get direction 'y_t)
+		    (get direction 's)
+		    (get direction 'noise)
+		    )))
+
+(defun lm-print-y,s,noise ()
+  (interactive)
+  (save-excursion
+    (set-buffer "*lm-y,s,noise*")
+    (insert "==============================\n")
+    (mapc 'lm-print-y,s,noise-int lm-directions)))
+
+(defun lm-print-smell-int (direction)
+  (insert (format "%S: smell: %S \n"
+		    (symbol-name direction)
+		    (get direction 'smell))))
+
+(defun lm-print-smell ()
+  (interactive)
+  (save-excursion
+    (set-buffer "*lm-smell*")
+    (insert "==============================\n")
+    (insert (format "tree: %S \n" (get 'z 't)))
+    (mapc 'lm-print-smell-int lm-directions)))
+
+(defun lm-print-w0-int (direction)
+  (insert (format "%S: w0: %S \n"
+		    (symbol-name direction)
+		    (get direction 'w0))))
+
+(defun lm-print-w0 ()
+  (interactive)
+  (save-excursion
+    (set-buffer "*lm-w0*")
+    (insert "==============================\n")
+    (mapc 'lm-print-w0-int lm-directions)))
+
+(defun lm-blackbox ()
+  (save-excursion
+    (set-buffer "*lm-blackbox*")
+    (insert "==============================\n")
+    (insert "I smell: ")
+    (mapc '(lambda (direction)
+	       (if (> (get direction 'smell) 0)
+		   (insert (format "%S " direction))))
+	    lm-directions)
+    (insert "\n")
+
+    (insert "I move: ")
+    (mapc '(lambda (direction)
+	       (if (> (get direction 'y_t) 0)
+		   (insert (format "%S " direction))))
+	    lm-directions)
+    (insert "\n")
+    (lm-print-wts-blackbox)
+    (insert (format "z_t-z_t-1: %S" (- (get 'z 't) (get 'z 't-1))))
+    (lm-print-distance)
+    (insert "\n")))
+
+(defun lm-print-wts-blackbox ()
+  (interactive)
+  (mapc 'lm-print-wts-int lm-directions))
+
+
+
+
+
+;;;_ + Simulation variables
+
+;;;_  - lm-nvar
+(defvar lm-nvar 0.0075 "affects a noise generator which was used in an
+earlier incarnation of this program to add a random element to the way
+moves were made. not used")
+;;;_  - lists of cardinal directions
+;;;_   : 
+(defvar lm-ns '(lm-n lm-s) "used when doing something relative to the
+  north and south axes")
+(defvar lm-ew '(lm-e lm-w) "used when doing something relative to the
+  north and south axes")
+(defvar lm-directions '(lm-n lm-s lm-e lm-w) "the cardinal directions")
+(defvar lm-8-directions '(
+			   (lm-n)     (lm-n lm-w)    (lm-s)
+			   (lm-s lm-w)  (lm-e)       (lm-s lm-e)
+			   (lm-n lm-w)  (lm-w)) 
+  "the full 8 possible directions.")
+;;;_  - learning parameters
+(defvar lm-bound 0.005 "the maximum that w0j may be.")
+(defvar lm-c 1.0 "a factor applied to modulate the increase in
+wij. used in the function lm-update-normal-weights")
+(defvar lm-c-naught 0.5 "a factor applied to modulate the increase in
+w0j. used in the function lm-update-naught-weights" )
+(defvar lm-initial-w0 0.0)
+(defvar lm-initial-wij 0.0)
+(defvar lm-no-payoff 0 "the amount of simulation cycles that have
+occurred with no movement. used to move the robot when he is stuck in
+a rut for some reason")
+(defvar lm-max-stall-time 3 "the maximum of amount of simulation
+cycles that the robot can get stuck in a place before lm-random-move
+is called to push him out of it")
+
+
+
+
+
+
+
+;;;_ + Randomizing functions
+;;;_  - lm-flip-a-coin ()
+(defun lm-flip-a-coin ()
+  (if (> (random 5000) 2500)
+      -1
+    1))
+;;;_   : lm-very-small-random-number ()
+(defun lm-very-small-random-number ()
+  (/
+   (* (/ (random 900000) 900000.0) .0001)))
+;;;_   : lm-randomize-weights-for (direction)
+(defun lm-randomize-weights-for (direction)
+  (mapc '(lambda (target-direction) 
+	     (put direction
+		  target-direction 
+		  (* (lm-flip-a-coin) (/  (random 10000) 10000.0))))
+	  lm-directions))
+;;;_   : lm-noise ()
+(defun lm-noise ()
+  (* (- (/ (random 30001) 15000.0) 1) lm-nvar))
+
+(defun lm-randomize-weights-for (direction)
+  (mapc '(lambda (target-direction) 
+	     (put direction
+		  target-direction 
+		  (* (lm-flip-a-coin) (/  (random 10000) 10000.0))))
+	  lm-directions))
+					      
+
+
+
+;;;_   : lm-fix-weights-for (direction)
+(defun lm-fix-weights-for (direction)
+  (mapc '(lambda (target-direction) 
+	     (put direction
+		  target-direction 
+		  lm-initial-wij))
+	  lm-directions))
+					      
+
+
+
+;;;_ + Plotting functions
+;;;_  - lm-plot-internal (sym)
+(defun lm-plot-internal (sym)
+  (lm-plot-square (lm-xy-to-index 
+		   (get sym 'x)
+		   (get sym 'y))
+		   (get sym 'sym)))
+;;;_  - lm-plot-landmarks ()
+(defun lm-plot-landmarks ()
+  (setq lm-cx (/ lm-board-width  2))
+  (setq lm-cy (/ lm-board-height 2))
+
+  (put 'lm-n    'x lm-cx)  
+  (put 'lm-n    'y 1)  
+  (put 'lm-n    'sym 2)
+
+  (put 'lm-tree 'x lm-cx)
+  (put 'lm-tree 'y lm-cy)
+  (put 'lm-tree 'sym 6)
+
+  (put 'lm-s    'x lm-cx)
+  (put 'lm-s    'y lm-board-height)
+  (put 'lm-s    'sym 3)
+
+  (put 'lm-w    'x 1)
+  (put 'lm-w    'y (/ lm-board-height 2))
+  (put 'lm-w    'sym 5)
+
+  (put 'lm-e    'x lm-board-width)
+  (put 'lm-e    'y (/ lm-board-height 2))
+  (put 'lm-e    'sym 4)
+
+  (mapc 'lm-plot-internal '(lm-n lm-s lm-e lm-w lm-tree)))
+
+
+
+;;;_ + Distance-calculation functions
+;;;_  - square (a)
+(defun square (a)
+  (* a a))
+
+;;;_  - distance (x x0 y y0)
+(defun distance (x x0 y y0)
+  (sqrt (+ (square (- x x0)) (square (- y y0)))))
+
+;;;_  - calc-distance-of-robot-from (direction)
+(defun calc-distance-of-robot-from (direction)
+  (put direction 'distance
+       (distance (get direction 'x)
+		 (lm-index-to-x (lm-point-square))
+		 (get direction 'y)
+		 (lm-index-to-y (lm-point-square)))))
+
+;;;_  - calc-smell-internal (sym)
+(defun calc-smell-internal (sym)
+  (let ((r (get sym 'r))
+	(d (calc-distance-of-robot-from sym)))
+    (if (> (* 0.5 (- 1 (/ d r))) 0)
+	(* 0.5 (- 1 (/ d r)))
+      0)))
+
+
+
+;;;_ + Learning (neural) functions
+(defun lm-f (x)
+  (cond 
+   ((> x lm-bound) lm-bound)
+   ((< x 0.0) 0.0)
+   (t x)))
+
+(defun lm-y (direction)
+  (let ((noise (put direction 'noise (lm-noise))))
+    (put direction 'y_t
+	 (if (> (get direction 's) 0.0)
+	     1.0
+	   0.0))))
+
+(defun lm-update-normal-weights (direction)
+  (mapc '(lambda (target-direction)
+	     (put direction target-direction
+		  (+
+		   (get direction target-direction)
+		   (* lm-c 
+		      (- (get 'z 't) (get 'z 't-1)) 
+		      (get target-direction 'y_t)
+		      (get direction 'smell)))))
+	  lm-directions))
+	     
+(defun lm-update-naught-weights (direction)
+  (mapc '(lambda (target-direction)
+	     (put direction 'w0
+		  (lm-f 
+		   (+
+		    (get direction 'w0)
+		    (* lm-c-naught
+		       (- (get 'z 't) (get 'z 't-1)) 
+		       (get direction 'y_t))))))
+	  lm-directions))
+
+
+
+;;;_ + Statistics gathering and creating functions
+
+(defun lm-calc-current-smells ()
+  (mapc '(lambda (direction) 
+	     (put direction 'smell (calc-smell-internal direction)))
+	  lm-directions))
+
+(defun lm-calc-payoff ()
+  (put 'z 't-1 (get 'z 't))
+  (put 'z 't (calc-smell-internal 'lm-tree))
+  (if (= (- (get 'z 't) (get 'z 't-1)) 0.0)
+      (incf lm-no-payoff)
+    (setf lm-no-payoff 0)))
+
+(defun lm-store-old-y_t ()
+  (mapc '(lambda (direction) 
+	     (put direction 'y_t-1 (get direction 'y_t)))
+	  lm-directions))
+
+
+
+;;;_ + Functions to move robot 
+      
+
+(defun lm-confidence-for (target-direction)
+  (+
+   (get target-direction 'w0)
+   (reduce '+
+    (mapcar '(lambda (direction)
+	       (* 
+		(get direction target-direction)
+		(get direction 'smell))
+			)
+	    lm-directions))))
+
+
+(defun lm-calc-confidences ()
+  (mapc '(lambda (direction) 
+	     (put direction 's (lm-confidence-for direction)))
+	     lm-directions))
+
+(defun lm-move ()
+  (if (and (= (get 'lm-n 'y_t) 1.0) (= (get 'lm-s 'y_t) 1.0))
+      (progn
+	(mapc '(lambda (dir) (put dir 'y_t 0)) lm-ns)
+	(message "n-s normalization.")))
+  (if (and (= (get 'lm-w 'y_t) 1.0) (= (get 'lm-e 'y_t) 1.0))
+      (progn
+	(mapc '(lambda (dir) (put dir 'y_t 0)) lm-ew)
+	(message "e-w normalization")))
+
+  (mapc '(lambda (pair)
+	     (if (> (get (car pair) 'y_t) 0)
+		 (funcall (car (cdr pair)))))
+	  '(
+	    (lm-n lm-move-up)
+	    (lm-s lm-move-down)
+	    (lm-e forward-char)
+	    (lm-w backward-char)))
+  (lm-plot-square (lm-point-square) 1)
+  (incf lm-moves))
+
+
+(defun lm-random-move ()
+  (mapc 
+   '(lambda (direction) (put direction 'y_t 0))
+   lm-directions)
+  (dolist (direction (nth (random 8) lm-8-directions))
+    (put direction 'y_t 1.0))
+  (lm-move))
+
+(defun lm-amble-robot ()
+  (interactive)
+  (while (> (calc-distance-of-robot-from 'lm-tree) 0)
+
+    (lm-store-old-y_t)
+    (lm-calc-current-smells)
+
+    (if (> lm-no-payoff lm-max-stall-time)
+	(lm-random-move)
+      (progn
+	(lm-calc-confidences)
+	(mapc 'lm-y lm-directions)
+	(lm-move)))
+
+    (lm-calc-payoff)
+
+    (mapc 'lm-update-normal-weights lm-directions)
+    (mapc 'lm-update-naught-weights lm-directions)
+    (lm-maybe-debug))
+
+  (let ((lm-res-str (format "%S moves." lm-moves)))
+    (if lm-debug
+	(lm-print-moves lm-res-str))
+    (message (format "%S moves." lm-moves))))
+
+;;;_  - lm-start-robot ()
+(defun lm-start-robot ()
+  "Signal to the Lm program that you have played.
+You must have put the cursor on the square where you want to play.
+If the game is finished, this command requests for another game."
+  (interactive)
+  (lm-switch-to-window)
+  (cond
+   (lm-emacs-is-computing
+    (lm-crash-game))
+   ((not lm-game-in-progress)
+    (lm-prompt-for-other-game))
+   (t
+    (let (square score)
+      (setq square (lm-point-square))
+      (cond ((null square)
+	     (error "Your point is not on a square. Retry !"))
+	    ((not (zerop (aref lm-board square)))
+	     (error "Your point is not on a free square. Retry !"))
+	    (t
+	     (progn
+	       (lm-plot-square square 1)
+
+	       (lm-store-old-y_t)
+	       (lm-calc-current-smells)
+	       (put 'z 't (calc-smell-internal 'lm-tree))
+
+	       (lm-random-move)
+
+	       (lm-calc-payoff)
+
+	       (mapc 'lm-update-normal-weights lm-directions)
+	       (mapc 'lm-update-naught-weights lm-directions)
+	       (lm-maybe-debug)
+	       (lm-amble-robot)
+	       )))))))
+
+
+
+;;;_ + Misc functions
+;;;_  - lm-init (auto-start save-weights)
+(defun lm-init (auto-start save-weights)
+
+  (setq lm-moves 0)
+
+  (lm-plot-landmarks)
+
+  (if lm-debug
+      (progn
+	(save-excursion
+	  (set-buffer (get-buffer-create "*lm-w0*"))
+    (erase-buffer)
+    (set-buffer (get-buffer-create "*lm-moves*"))
+    (set-buffer (get-buffer-create "*lm-wts*"))
+    (erase-buffer)
+    (set-buffer (get-buffer-create "*lm-y,s,noise*"))
+    (erase-buffer)
+    (set-buffer (get-buffer-create "*lm-smell*"))
+    (erase-buffer)
+    (set-buffer (get-buffer-create "*lm-blackbox*"))
+    (erase-buffer)
+    (set-buffer (get-buffer-create "*lm-distance*"))
+    (erase-buffer))))
+
+
+  (lm-set-landmark-signal-strengths)
+
+  (mapc '(lambda (direction)
+	     (put direction 'y_t 0.0))
+	  lm-directions)
+
+  (if (not save-weights)
+      (progn
+	(mapc 'lm-fix-weights-for lm-directions)
+	(mapc '(lambda (direction)
+		   (put direction 'w0 lm-initial-w0))
+	lm-directions))
+    (message "Weights preserved for this run."))
+
+  (if auto-start
+      (progn
+	(lm-goto-xy (1+ (random lm-board-width)) (1+ (random lm-board-height)))
+	(lm-start-robot))))
+    
+    
+
+;;;_  - something which doesn't work
+; no-a-worka!!
+;(defum lm-sum-list (list)
+;  (if (> (length list) 0)
+;      (+ (car list) (lm-sum-list (cdr list)))
+;    0))
+; this a worka!
+; (eval  (cons '+ list))
+;;;_  - lm-set-landmark-signal-strengths ()
+;;; on a screen higher than wide, I noticed that the robot would amble
+;;; left and right and not move forward. examining *lm-blackbox*
+;;; revealed that there was no scent from the north and south
+;;; landmarks, hence, they need less factoring down of the effect of
+;;; distance on scent.
+
+(defun lm-set-landmark-signal-strengths ()
+
+  (setq lm-tree-r       (* (sqrt (+ (square lm-cx) (square lm-cy))) 1.5))
+
+  (mapc '(lambda (direction) 
+	     (put direction 'r (* lm-cx 1.1)))
+	lm-ew)
+  (mapc '(lambda (direction) 
+	     (put direction 'r (* lm-cy 1.1)))
+	lm-ns)
+  (put 'lm-tree 'r lm-tree-r))
+
+
+
+
+
+;;;_ + lm-test-run ()
+
+(defun lm-test-run ()
+
+  (interactive)
+
+  (lm 1)
+
+  (dotimes (scratch-var 100)
+
+    (lm 2)))
+
+
+
+;;;_ + lm: The function you invoke to play
+
+;;;###autoload
+(defun landmark (parg)
+  "Start an Lm game.
+If a game is in progress, this command allows you to resume it.
+Here is the relation between prefix args and game options:
+
+prefix arg | robot is auto-started | weights are saved from last game
+---------------------------------------------------------------------
+none / 1   | yes                   | no
+       2   | yes                   | yes
+       3   | no                    | yes
+       4   | no                    | no
+
+You start by moving to a square and typing \\[lm-start-robot].
+Use \\[describe-mode] for more info."
+  (interactive "p")
+
+  (setf n nil m nil)
+  (lm-switch-to-window)
+  (cond
+   (lm-emacs-is-computing
+    (lm-crash-game))
+   ((or (not lm-game-in-progress)
+	(<= lm-number-of-moves 2))
+    (let ((max-width (lm-max-width))
+	  (max-height (lm-max-height)))
+      (or n (setq n max-width))
+      (or m (setq m max-height))
+      (cond ((< n 1)
+	     (error "I need at least 1 column"))
+	    ((< m 1)
+	     (error "I need at least 1 row"))
+	    ((> n max-width)
+	     (error "I cannot display %d columns in that window" n)))
+      (if (and (> m max-height)
+	       (not (eq m lm-saved-board-height))
+	       ;; Use EQ because SAVED-BOARD-HEIGHT may be nil
+	       (not (y-or-n-p (format "Do you really want %d rows " m))))
+	  (setq m max-height)))
+    (message "One moment, please...")
+    (lm-start-game n m)))
+  (eval (cons 'lm-init 
+	      (cond 
+	       ((= parg 1)  '(t nil))
+	       ((= parg 2)  '(t t))
+	       ((= parg 3)  '(nil t))
+	       ((= parg 4)  '(nil nil))
+	       (t '(nil t))))))
+	       
+;;;_ + Local variables
+
+;;; The following `outline-layout' local variable setting:
+;;;  - closes all topics from the first topic to just before the third-to-last,
+;;;  - shows the children of the third to last (config vars)
+;;;  - and the second to last (code section),
+;;;  - and closes the last topic (this local-variables section).
+;;;Local variables:
+;;;outline-layout: (0 : -1 -1 0)
+;;;End:
+
+
+;;; landmark.el ends here