Function lambda_calculus::pair::pair

pub fn pair() -> Term

Produces a Church-encoded pair; applying it to two other terms puts them inside it.

PAIR := λxyz.z x y = λ λ λ 1 3 2

Example

use lambda_calculus::pair::pair;
use lambda_calculus::arithmetic::{zero, one};
let pair01 = pair().app(zero()).app(one());

assert_eq!(pair01.fst_ref(), Ok(&zero()));
assert_eq!(pair01.snd_ref(), Ok(&one()));