(DEFUN SPACE (N)
  (COND ((< N 0) (PRINC "ERROR!"))
        ((ZEROP N) NIL)
        (T (PRINC " ") (SPACE (1- N)))))

(DEFUN PLOT-ONE-POINT (SYM VAL)
  (SPACE VAL)
  (PRINC SYM)
  (TERPRI))

(DEFUN PLOT-POINTS (SYM YLIS)
  (MAPCAR #'(LAMBDA (Y) (PLOT-ONE-POINT SYM Y)) YLIS))

(DEFUN GENERATE (M N)
  (COND ((> M N) NIL)
        (T (CONS M (GENERATE (1+ M) N)))))

(DEFUN SQUARE (X)
  (* X X))

(DEFUN MAKE-GRAPH ()
  (PRINC "FUNCTION TO GRAPH? ")
  (SETQ FUNC (READ))
  (PRINC "STARTING VALUE? ")
  (SETQ START (READ))
  (PRINC "ENDING VALUE? ")
  (SETQ END (READ))
  (PRINC "PLOTTING SYMBOL? ")
  (SETQ SYM (READ))
  (PLOT-POINTS SYM (MAPCAR FUNC (GENERATE START END)))
  (PRINC " "))