Here is the learning rate parameter whose value was fixed for a specific code to achieve a balance between the accuracy and the rate of learning. We suggest = 0.0005 by default as it is used in FUSE, however in MC-EMMA we have = 0.01 to increase the learning process and this value can be used for relatively short runs (~2,000 steps). ∇ ( , , ) is the gradient of the probability of taking action :