Well, it depends how you take it. The fact that the halting problem is undecidable tells us that there is no algorithm to tell if an algorithm will ever halt fo

Well, it depends how you take it. The fact that the halting problem is undecidable tells us that there is no algorithm to tell if an algorithm will ever halt for some input. This implies that the best we can do if we want to find out if an arbitrary algorithm A will halt for some input B is to run A with input B. We may still never find out, but we also have no better way.