> > The number of times I have seen junior programmers try to solve the halting problem would make you weep.

> In what context?

The problem is that they don't recognize it as the "Halting Problem". It will be something like "Well, we can scan this thing to see if it does X or Y." No, actually you can't because "Doesn't terminate" is also an option. Oops. That's the Halting Problem.

In digital design, non-causal logic is a similar pitfall. Offline DSP algorithms can look backward and forward in time. If, however, you try to apply such a forward looking algorithm to a real-time system that needs an answer on the same time as the current sample, you wind up accidentally creating non-causal logic and wondering why your algorithm isn't working.