# TODO List

- [ ] Half a page, that is 25% of the total available space of 2 pages, is spent on the example of combinatory logic (CL), but then the example is not connected to the abstract framework it was intended to illustrate. 
- [ ] Very concretely, the functors Σ and B should be instantiated to CL, and then also the refinement of them presented in the "separability" part. 
- [ ] This counterexample takes around 15% of the total space, and these 15% could be used instead to connect the abstract framework to the CL example. [Worth mentioning that the other reviewer was happy with the text!]
- [ ] Category C, what do its objects and morphisms denote?
> The objects of C are representing sets of terms, morphisms functions. 
- [ ] What is the signature functor Σ for the case of xCL?
> Σ is the "non-recursive" presentation of the language of xCL, e.g.
   ```haskell
   data Σ X = I | K | S | K' X | S' X | S'' X X | App X X
   ```
- [ ] What is the behavior functor B?
> Here I am lost with my current background knowledge, as I would expect now some relation specifying the operational semantics, but B targets C.
- [ ] Likewise what are then Σᵥ, Σ_c, D and T?
- [ ] Guessing that X is for the lhss in accordance with paper [4], I do not understand why B(X,Y) becomes contravariant in X when in [4] it was covariant.
- [ ] So, if the xCL example shall be of any use in this abstract, B needs to spelled out for xCL.