Bibliography (13):

1. https://qntm.org/hypertime

2. Data.Sequence

3. A_->_%5Ba%5D

4. https://hoogle.haskell.org/?hoogle=tail

5. A_->_(A_->_a)_->_%5Ba%5D

6. Iterate

7. Zipper

8. Roll Your Own Window Manager: Tracking Focus With a Zipper

9. ListZipper: Simple Zipper for Lists

10. Wikipedia Bibliography:

    1. A series and B series

    2. Gap buffer  :

       https://en.wikipedia.org/wiki/Gap_buffer

    3. Zipper (data structure)  :

       https://en.wikipedia.org/wiki/Zipper_(data_structure)

    4. Purely functional data structure