"neural_net.ipynb" contains the simple neural network capable of learning a vector-input Boolean function.
usage notes for the handwritten letter learner "nn_MNIST_v2.ipynb":
please download "data.zip" as well, and decompress data.zip into a folder "data" inside the folder, where "nn_MNIST_v2.ipynb" is stored. This is necessary, because "nn_MNIST_v2.ipynb" will load the MNIST handwritten letters dataset from the "data" subfolder.