Defining Reward for Deep Reinforcement Learning? • /r/MachineLearning

I am designing a neural network in Lasagne, a Theano based Deep Learning Library. I am trying to program a simple, Reinforcement Learning network, but am running into a road block in defining the loss function. Basically, the input can be thought of as a location of the AI. The AI needs to get closer to a fixed destination point. The distance can be calculated by the input alone.