- The halting problem is “undecidable”: there’s no algorithm which can tell you if an arbitrary program with an arbitrary input will halt or not. IE, if you give me a proposed “halt-detector”, I can inspect it and come up with a program and input for which it would give the wrong answer.
The thing that hath been, it is that which shall be; and that which is done is that which shall be done: and there is no new thing under the sun.
Ecclesiastes 1:9 KJV