A Layers for deep learning, that consists on exponentiating all vector elements and normalize them to so sum to unity.
σ(y)≡ey∑ieyi\mathbf{\sigma}(\mathbf{y}) \equiv \frac{e^\mathbf{y}}{\sum_i e^{y_i}}σ(y)≡∑ieyiey
where the mathematical operations are element-wise.