Try a fix for the preorder reasoning error
Try a fix for the preorder reasoning error

Correct the dependency in `FastDerivation` to use the RHS in `step`
Try to avoid shadowing `y` in the LHS of `Calc`

mmhelloworld/idris-jvm,mmhelloworld/idris-jvm,mmhelloworld/idris-jvm,mmhelloworld/idris-jvm,mmhelloworld/idris-jvm,mmhelloworld/idris-jvm