Thank you ! Haven ' t seen any replicants ' round Tokyo lately <| sep |> Are you just being intimidated by the symbolic modal logic ? No , I ' m not intimidated , I happen to know much about formal logic . That ' s why I ' m not impressed by that prestigious jargon , I do understand it . But it is meant to intimidate you into accepting premises that are not acceptable and a conclusion that doesn ' t follow . If a simple argument can refute a proof , then the proof isn ' t sound , even if it uses complicated and hard to understand jargon . As arguments goes , the simpler , the better . That ' s why I wasn ' t answering prestigious jargon with even more prestigious jargon . The actual proof was likely much more complexLikely , so you do admit that you don ' t understand it ? Why do you accept as true an argument you don ' t even understand ? and devoid of the common sense explanations such as I ' ve quoted above . Yes , and that ' s the problem . There is no link between what they prove and the common sense explanation . Maybe they did prove that KP pp Kp and NonO pp Kp are contradicting one another but they certainly didn ' t prove that if all truths are knowable , then all truths are known to something and I was answering to that claim that is clearly and obviously wrong .