> Note that the article has a comment by Yann LeCun (hopefully it's not an impersonator).

i wouldnt be surprised if it was lecun. colah's illustrations on nonlinear transformations have made it into several lecun papers, including the following [nature review]( https://www.nature.com/articles/nature14539).

Following the link from Yann LeCun's comment in the parent post one can find this neat library: DiffSharp http://diffsharp.github.io/DiffSharp/