Zizhao Chen

## Pull Request This template outlines which information should be contained in a pull request description. Please adhere to this structure as closely as possible and ensure that you can...

`flip filter` fails to unify: where do the constraints go?

3

`flip filter` and `flip map` used to work (at least in January) and now it throws a type error: ``` :t (flip filter) Type error: Expected: (a -> b ->...

Support AD on ADTs that have tangent types equal to the primal types

2

Currently, `grad` does not work on data types such as `List`. For example: ``` ls = (AsList _ [1.,2.,3.]) def sumList ((AsList _ arr) : List Float): Float = sum...