Underun

Underun is an esoteric programming language created by User:Yayimhere. It combines the Unlambda operators d & c with Sea's &, Underload's () and ~ and a special operator ..

Rewrite rules

(Note that c will be not listed here, as it are more complex than a simple rewrite, to my knowledge).

Below are the rewrite rules:

(a) & -> (K) (S') a
(b) (a) K -> a
(d) (c) (b) (a) S' -> ((d) c) a (d) b
(b) (a) ~ -> (a) (b)
a . -> (a)
(b) (a) d -> {(b) ^ .} a
(a) ^ -> a

Note that c is also applied like this:

(a) c = `c (a)

Also note that brackets can be represented as {..}.