anchor.diff: -;; Copyright © 2002 Donnie Cameron
  +;; Copyright © 2002-2018 Donnie Cameron
   ;;
   ;; ANN stands for Artificial Neural Network. This is a simple
   ;; implementation of the standard backpropagation neural network.
  
positive.code:              (incf correct)))
         finally (return (/ (truncate (* (/ correct total) 10000)) 100.0)))))
  
  (defun training-circle-points (count &key stats)
    (if stats
        (loop for a from 1 to count
           for x = (* (if (zerop (random 2)) 1 0) (random 1.0))
  
negative.code:    (randomize :accessor randomize :type boolean :initform nil)
     (anneal :accessor anneal :type boolean :initform nil)
     (stop-training :accessor stop-training :type boolean :initform nil)
     (shock :accessor shock :type boolean :initform nil)
     (last-report-time :accessor last-report-time :type integer :initform nil))
    (:documentation "Describes a standard multilayer, fully-connected backpropagation neural network."))
  
  (defmethod output-layer ((net t-net))
  