Implements a simple back-propogation neural network.
(setf network (newdeltanetwork '(2 2)) will create a two-layer network with 2 input and 2 output neurons.
Training against this network inside a loop is simple:
(setf network (deltalearn network '(((1 0) (0 1)) ((0 1) (1 0)))))
The training list consists of inputs to the network and expected outputs.
See the test folder for examples.