Newest at the top
| 2024-05-13 21:44:59 +0200 | <mauke> | ooh, I know what this is |
| 2024-05-13 21:44:43 +0200 | <int-e> | (I feel that a complete solution to the original problem should exhibit a model. Or both :)) |
| 2024-05-13 21:44:37 +0200 | <monochrom> | But I don't worry about it because it is then the question's fault. |
| 2024-05-13 21:44:37 +0200 | rekahsoft | (~rekahsoft@184.148.6.204) |
| 2024-05-13 21:43:50 +0200 | <monochrom> | You are right, but since your version contains a contradiction (equivalently a fixed point equation that has no solution), every complete proof system will prove the same nonsense. This means even natural deduction is vulnerable. |
| 2024-05-13 21:43:40 +0200 | <int-e> | It's not. It's just assumed that the assumptions are consistent, and in your case they aren't. |
| 2024-05-13 21:40:54 +0200 | <mauke> | but what makes this derivation different from the "proof" in the paper? |
| 2024-05-13 21:40:21 +0200 | <mauke> | I consider this derivation defective because you can't just plug some (possibly contradictory) statements into a formula, derive a result according to some logical rules, and then call it a day |
| 2024-05-13 21:39:15 +0200 | tromp | (~textual@92-110-219-57.cable.dynamic.v4.ziggo.nl) |
| 2024-05-13 21:39:05 +0200 | <mauke> | yes :-) |
| 2024-05-13 21:38:57 +0200 | <int-e> | mauke: You can also prove that the portrait is in the silver casket, so you get two portraits! |
| 2024-05-13 21:37:40 +0200 | <monochrom> | My supervisor (that would be the Hehner mentioned in the paper) changed that to the less morbid: The teacher says there is a surprise test this week. :) |
| 2024-05-13 21:36:07 +0200 | <int-e> | has anybody mentioned https://en.wikipedia.org/wiki/Unexpected_hanging_paradox yet? (at least not by this name) |
| 2024-05-13 21:35:51 +0200 | <mauke> | true ==> true \/ P(G) ==> (S = -G) \/ P(G) ==> (S = -S) \/ P(G) ==> false \/ P(G) ==> P(G) |
| 2024-05-13 21:34:43 +0200 | <mauke> | ok, what's wrong with the following? consider a similar situation but with the gold inscription G being "the silver inscription is true" and the silver inscription S being "the gold inscription is false". I can then formally prove that the portrait is in the gold casket (P(G)) in a derivation similar to that in the paper. |
| 2024-05-13 21:33:20 +0200 | yin | (~yin@user/zero) |
| 2024-05-13 21:28:22 +0200 | <monochrom> | Right? We know of escape rooms that are way more logical than the lunatic. :) |
| 2024-05-13 21:27:04 +0200 | <monochrom> | For the lunatic case, I may consider adding the simulation hypothesis and say that I'm in a simulation, not the least because why else there is lunatic targetting me, so I open both boxes to ensure efficient end of the simulation. >:) |
| 2024-05-13 21:25:26 +0200 | <ncf> | in other words, logic puzzles are not a survival manual |
| 2024-05-13 21:24:44 +0200 | <int-e> | ncf: ah. how long has... oh god. |
| 2024-05-13 21:24:37 +0200 | <monochrom> | In the same way the sentinel puzzle begins with "you don't know whether he's honest or lying but it is one of them". |
| 2024-05-13 21:24:19 +0200 | <ncf> | if you refuse to read the inscriptions there is no puzzle |
| 2024-05-13 21:24:11 +0200 | <ncf> | we've been over this <ncf> the hidden piece of information is that both sentences are meaningful |
| 2024-05-13 21:23:49 +0200 | <tomsmeding> | it draws a conclusion from the inscriptions |
| 2024-05-13 21:23:47 +0200 | <int-e> | the inscription could be meaningless |
| 2024-05-13 21:23:46 +0200 | <monochrom> | It begins with someone who makes sure that each sentence is honest or lying. |
| 2024-05-13 21:23:34 +0200 | <tomsmeding> | mauke: the article does not draw a conclusion about the caskets |
| 2024-05-13 21:23:10 +0200 | <mauke> | because the gold inscription is false |
| 2024-05-13 21:23:05 +0200 | <mauke> | in the original puzzle, you know that at least one inscription does not apply to reality |
| 2024-05-13 21:23:03 +0200 | <monochrom> | But the casket logic puzzle does not begin with someone who is a violent lunatic who gates my guts. |
| 2024-05-13 21:23:01 +0200 | <tomsmeding> | it just claims that it is the logical conclusion of the inscriptions |
| 2024-05-13 21:22:54 +0200 | <tomsmeding> | the article does not claim that the portrait is _actually_ in that casket |
| 2024-05-13 21:22:37 +0200 | <tomsmeding> | whether the conclusion applies to reality is then predicated on whether you believe that the inscriptions apply to reality |
| 2024-05-13 21:22:35 +0200 | <mauke> | yes, but what good will that do you? |
| 2024-05-13 21:22:21 +0200 | <tomsmeding> | mauke: you can still do logic on the inscriptions |
| 2024-05-13 21:21:22 +0200 | <mauke> | which box do you open? |
| 2024-05-13 21:21:18 +0200 | <mauke> | also, there are inscriptions on the boxes or whatever |
| 2024-05-13 21:21:11 +0200 | <mauke> | I am a violent lunatic who hates your guts. I have trapped you in a locked room. In the room, there are two boxes. One of them contains a key that lets you out, the other contains a bomb that goes off when you open the box and blows you to bits. |
| 2024-05-13 21:20:48 +0200 | euleritian | (~euleritia@ip4d16fc38.dynamic.kabel-deutschland.de) |
| 2024-05-13 21:20:30 +0200 | euleritian | (~euleritia@dynamic-176-006-186-214.176.6.pool.telefonica.de) (Read error: Connection reset by peer) |
| 2024-05-13 21:19:58 +0200 | <mauke> | I think I need to reformulate this problem a bit |
| 2024-05-13 21:18:49 +0200 | <ncf> | mauke: if i were to formalise this in, say, Agda, i would postulate that there is a boolean type Casket = gold | silver, a predicate HasPainting : Casket → DecProp such that HasPainting(gold) ∨ HasPainting(silver), a DecProp Gold such that Gold ≃ ¬HasPainting(gold), and a DecProp Silver such that Silver ≃ ExactlyOne Gold Silver, and then proceed to show that HasPainting(gold) holds |
| 2024-05-13 21:18:16 +0200 | <tomsmeding> | it clearly threw mauke off |
| 2024-05-13 21:18:13 +0200 | zzz | (~yin@user/zero) (Quit: leaving) |
| 2024-05-13 21:18:08 +0200 | <tomsmeding> | which is admittedly unrelated, but at the level of preciseness that you need in such a context |
| 2024-05-13 21:17:51 +0200 | <tomsmeding> | there is the implicit "the" |
| 2024-05-13 21:17:38 +0200 | <monochrom> | Yeah there is the assumption that this self-reference has a solution. |
| 2024-05-13 21:15:45 +0200 | <tomsmeding> | although I agree that if you start writing self-referential sentences, you better be damn clear about what exactly you mean |
| 2024-05-13 21:15:26 +0200 | <tomsmeding> | this discussion was about interpreting the puzzle's text too literally so that you miss the point of the puzzle |
| 2024-05-13 21:14:56 +0200 | <tomsmeding> | I don't think this discussion was about that :) |