^

^ is an esolang by User:None1. It is the smallest esolang that is impossible to solve the halting problem.

Commands

The only command

^

performs an infinite loop if this program halts otherwise it does nothing.

Uncomputability proof

If this esolang in computable, consider this program:

^

If it halts, it will not halt, otherwise it will halt. So this esolang is uncomputable.

To sum up, this esolang is not computable for it can solve the halting problem.

Interpreter

It is of course impossible to make an interpreter because it is uncomputable.