What exactly is the halting problem?

Question

Whenever people ask about the halting problem as it pertains to programming, people respond with \"If you just add one loop, you\'ve got the halting program and therefore yo

Answer 1

This has been beaten to death so well that there is actually a poetic proof, written in the style of Lewis Carroll Dr. Seuss by Geoffrey Pullum (he of Language Log fame).

Funny stuff. Here's a taste:

Here’s the trick that I’ll use – and it’s simple to do.
I’ll define a procedure, which I will call Q,
that will use P’s predictions of halting success
to stir up a terrible logical mess.

...

No matter how P might perform, Q will scoop it:
Q uses P’s output to make P look stupid.
Whatever P says, it cannot predict Q:
P is right when it’s wrong, and is false when it’s true!