Let's reduce the operations on rank-1 arrays (lists) down to very basic functions.
Two views on lists:
- A list is a function from indices to values
- A list is a free monoid
The first view gives ↕n
, i⊑x
and x⊏y
, which correspond to the identity function, application
and composition, and also gives f¨x
and x f¨ y
.