anchor.diff:    (let ((fig-2-15-a (make-fa '((q7 :epsilon q5) (q7 :epsilon q8)
                                  (q5 1 q6)
                                  (q6 :epsilon q5) (q6 :epsilon q8))
  -                             'q7 'q8))
  +                             'q7 (finite-set 'q8)))
           (fig-2-15-b (make-fa '((q3 0 q4)
                                  (q4 :epsilon q7)
                                  (q7 :epsilon q5) (q7 :epsilon q8)
                                  (q5 1 q6)
                                  (q6 :epsilon q5) (q6 :epsilon q8))
  -                             'q3 'q8))
  +                             'q3 (finite-set 'q8)))
           (fig-2-15-c (make-fa '((q9 :epsilon q1) (q9 :epsilon q3)
                                  (q1 1 q2)
                                  (q2 :epsilon q10)
  
positive.code:   (let* ((fig-3-56  '(:concatenation (:closure (:union a b)) a b b))
           (fig-3-63 (make-fa '((0 b 0) (0 a 1) (1 a 1) (1 b 2) (2 a 1) (2 b 3)
                                (3 a 1) (3 b 0))
                              0 3))
           (my-fig-3-36 (regex->nfa fig-3-56))
           (my-fig-3-63 (nfa->dfa my-fig-3-36)))
  
  
negative.code:   (let ((fig-1-42 (make-fa '((1 :epsilon 3) (1 b 2)
                               (2 a 2) (2 a 3) (2 b 3)
                               (3 a 1))
                             1 (finite-set 1)))
          (fig-1-44 (make-fa '((2 a 23) (2 b 3)
                               (3 a 13)
                               (13 a 13) (13 b 2)
  