anchor.diff:  (defun train-mnist-dbm (dbm)
     (log-msg "Starting to train DBM.~%")
     (train (make-sampler *training-images*
  -                       :max-n (* 0 (length *training-images*))
  +                       :max-n (* 200 (length *training-images*))
                          :sample-visible-p t)
            (make-instance 'mnist-dbm-trainer
                           :n-particles 100
  
positive.code:                                                     (length *test-images*))
                                        dbm))
             (n-inputs trainer))
    (let ((counters-and-measurers
           (make-bm-reconstruction-misclassification-counters-and-measurers dbm)))
      (when counters-and-measurers
  
negative.code: 
  (defmethod log-test-error ((trainer mnist-dbm-trainer) (dbm mnist-dbm))
    (describe-trainer trainer)
    (save-weights (merge-pathnames (format nil "mnist-2-~A.dbm"
                                           (floor (n-inputs trainer)
                                                  (length *training-images*)))
                                   *mnist-dir*)
                  *dbm/2*)
    (log-msg "DBM TEST RMSE: ~{~,5F~^, ~} (~D)~%"
             (map 'list
                  #'get-error
  