anchor.diff:  
   (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
  
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: (defun train-mnist-dbm (dbm)
    (log-msg "Starting to train DBM.~%")
    (train (make-sampler *training-images*
                         :max-n (* 200 (length *training-images*))
                         :sample-visible-p t)
           (make-instance 'mnist-dbm-trainer
                          :n-particles 100
  