[RFC] Differentiable tensor expression (Create and verify backward op automatically)

Glad to see autodiff is already in progress! I think this rfc can be withdrew since this is exactly what autodiff is doing.

Now I am very curious about current progress of autodiff with some questions.

  • If I have some common neural network structure such as resnet50 at hand, can I just use autodiff to get backward computation graph?
  • Is there some description about common ops which can be coveraged by autodiff?
  • Can te.scan() be supported?