Single Arg

Single Arg

Paradigm(s)	Functional
Designed by	User:Hakerh400
Appeared in	2026
Computational class	Turing complete
Major implementations	Implemented
File extension(s)	.txt

Single Arg is an esolang invented by User:Hakerh400 in 2026.

Syntax

Source code consists of a term.

term ::= '.' | '-' | '+' | '<' | '>'
  | '{' term '}'
  | term term          (application, left‑associative)
  | '(' term ')'       (grouping, transparent)

Parentheses () exist only for disambiguation and have no semantic effect. Whitespace is ignored.

Reduction rules

In the following, X, Y, Z are arbitrary terms, while C is one of -, +, <, >.

{.} X      →  X
{{X}} Y    →  {X}
{C} Y      →  C
{X Y} Z    →  {X} Z ({Y} Z)
< (+ X Y)  →  X
> (+ X Y)  →  Y
- X Y Z    →  X (+ Y Z)

Computational class

The language is Turing complete because it can encode the SKI combinator calculus:

I  →  {.}
K  →  -<
S  →  -(-{<(<.)(>.)(>(<.)(>.))})

External resources

• Interpreter