I would define paradox specifically as the case involved in the proof of the 2-undecidability halting problem, namely, functions of this kind: def do_opposite(

I would define paradox specifically as the case involved in the proof of the 2-undecidability halting problem, namely, functions of this kind: def do_opposite(): if is_halting(do_opposite): loop_forever() That's the paradox function which allegedly proves it's not worth attempting to decide {halt, loop} and so that (and other functions with the same behavior) would belong in the paradox category.