* Refactor contraction and add unit tests
* Fix typo; Fix TestConv.test_elu failure due to some ones in old_shape
* Add push permute test cases
* Fix mypy type annotation check error
* Add contraction unit test; Reshape to higher dimension is not contraction
* behavior is correct without VALIDHACKS
* simple div and mod
* fix tests
* no negative variables
* alt form is correct
* still correct
* bug in mulnode
* at least validhacks works now
* cleanups
* test validhacks, and to_image_idx
* cache compare key
* tests and __neg__