For starters, what if you want to differentiate through code that traverses a collection, for example: val x = ... ys.map(y => y + x) Each loop iterat

For starters, what if you want to differentiate through code that traverses a collection, for example: val x = ... ys.map(y => y + x) Each loop iteration needs to contribute a gradient update to x, which is defined in an outer scope. And what if y => y + x is not given as an inline lambda, but defined elsewhere. It doesn't seem like your blog posts discusses any such cases.