| Sym. | Bird | λ-Calculus | Use | Haskell |
|---|---|---|---|---|
| I | Idiot | λa. a | identity | id |
| M | Mockingbird | λf. ff | self-application | (cannot define) |
| K | Kestrel | λab. a | first, const | const |
| KI | Kite | λab. b (= KI) | second | const id |
- Note: The
KIKite is expressed above asλab. b. Which is 𝛼-equivalent toλxy. y. - But that can also be expressed as
KIaka as(λxy. y) (λz. z). - See also colored ink notes from today in JH CS Notebook #4.