anchor.diff:        (let ((errors (map 'list
                            #'get-error
                            (bm-mean-field-errors (make-sampler *test-images*
  -                                                             :max-n 1000
  -                                                             #+nil
  +                                                             :max-n #+nil
  +                                                             1000
                                                                (length
                                                                 *test-images*)
                                                                :omit-label-p t)
  
positive.code:            (map 'list
                  #'get-error
                  (dbn-mean-field-errors (make-sampler *test-images*
                                                       :max-n 1000
                                                       #+nil
                                                       (length *test-images*))
                                         (dbn rbm) :rbm rbm))
             (n-inputs trainer))
  
negative.code:            (map 'list
                  #'get-error
                  (bm-mean-field-errors (make-sampler *test-images*
                                                      :max-n #+nil
                                                      1000
                                                      (length *test-images*))
                                        dbm))
             (n-inputs trainer))
    (let ((counters-and-measurers
  