Dropout code appears to be working properly.   Then, how to proceed?  ;;; from recent commits: Continue to make progress.  Still have to get network display working correctly.  Dropout well may allow the maximum across-hidden-layer learning of "each example's applicable information."  Without dropout the earlier layers could completely isolate the learning of information that would/could be useful in determining the weights in the higher hidden layers. -- as well as in the output layer.  Dropout may allow us to see/learn-about  both (1) the forest through the tress, and (2) the trees through the forest!!  Also, gradually increasing prob of enabled neurons.  Use in recurrent nets.  Previous, important notes:  Now working on 4Class problem to illustrate "binding of multiple cluster-pairs" with 3rd and 4th inputs that allow very tight clusters and GREAT generalization IF the appropriate cluster-pairs are "bound together" in multiple ways!!  Yipee.