title: How does keras define "accuracy" and "loss"?
body: <p>I can't find how Keras defines "accuracy" and "loss".  I know I can specify different metrics (e.g. mse, cross entropy) - but keras prints out a standard "accuracy".  How is that defined? Likewise for loss: I know I can specify different types of regularization -- are those in the loss?</p>
  
  <p>Ideally, I'd like to print out the equation used to define it; if not, I'll settle for an answer here.</p>