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# Lion and Unicorn II.

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Lion and Unicorn II. - Back to the Logic Problems

Alice came across a lion and a unicorn in a forest of forgetfulness. Those two are strange beings. The lion lies every Monday, Tuesday and Wednesday and the other days he speaks the truth. The unicorn lies on Thursdays, Fridays and Saturdays, however the other days of the week he speaks the truth.

Lion said: Yesterday I was lying and two days after tomorrow I will be lying again.

Which day did he say that?

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Lion and Unicorn II. - solution

This conjunction is true only if both parts are true. The first part is true only on Thursday, but the second part is a lie then (Sunday is not a lying day of the Lion). So the whole statement can never be true (at least one part is not true). Therefore the Lion could have made the statement on Monday, on Tuesday and even on Wednesday.

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unless i have read the question wrong i think the lion could have only made this statement on the monday.

because the lion lies on tuesday and wednesday he cannot tell the truth. but in the first part of the riddle he states " yesterday i was lying" which is true but on tuesday and wednesday he can only lie

which makes either the riddle wrong or the answer wrong

prove me wrong

Quwandong

p.s

great job on the other riddels though keep em coming

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My solution is correct because logical conjunction is true if and only if both parts of the sentence are true (and not only if one part is true as you wrote). For more check http://en.wikipedia.org/wiki/Logical_conjunction

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I agree with quwandon, normaly people don't have this level of logic classes. Though I understand your point of view "for a statment to be false only one part of the statment needs be false"/"for a statment to be true, all parts of a stament needs be true". However again I belive the key word here is the "lion ALWAYS lies on mon-wed" (not "the lion could lie") so all parts of the stament has to be either lies or truths to satisfy the initial contition of the problem, the lion couldn't lie or tell the truth in the same day. Of course a whole new argument could be made if the day changed as he was making the statment, but I'd rather not get into that as it probably wasn't intended by the author of this logic statment. I think your trapped in the thinkings of your logic class (I'm assuming you've taken some form of phycology, which I haven't so I really shouldn't be criticyzing you).

My solution is correct because logical conjunction is true if and only if both parts of the sentence are true (and not only if one part is true as you wrote). For more check http://en.wikipedia.org/wiki/Logical_conjunction

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I have just found another site applying the same logic as I do - and for the same kind of puzzle. It is a difference saying 2 parts of 1 sentence and saying the same in 2 separate sentences. Check numbers 37) and 38) on page <!-- m --><a href="http://www.ocf.berkeley.edu/~yzuev/puzzles.html#alice" target="_blank">http://www.ocf.berkeley.edu/~yzuev/puzzles.html#alice</a><!-- m -->

Would be interesting to watch 2 philosophers argue about this puzzle

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I can see the reasoning for your answer: since the entire statement can never be true the lion would have to say it on a lying day... and because it is the whole statement that is the lie - it doesn't matter that parts of it are true. (but I think it the most correct for the lion to say it on Monday)

If the statement was actually two statements: "Yesterday I was lying" and "2 days after tomorrow I will lie again" ... then On Tuesday and Wednesday, the lion would be lying for everything ... so the first part "yesterday I was lying..." would be a truth and not something the lion would say on those days... this would actually make the first part of the statement false -- (even though the fact itself could be true -- it is that the lion would or would not say it that is in question)... and the second part" and two days after tomorrow I will be lying again" would be would be a True statement (being a lie on a lying day for the lion). F+T=F

And in that case then only day that it would actually work is MONDAY -- the lion would be lying: so all the statement facts would be lies... yesterday (Sunday) he was NOT lying (but he would say he was) and two days after tomorrow (Thursday) he would NOT be lying again (but he would say he was)... so T+T=T

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Monday is the easiest answer because both parts of the sentence will be false =D But yes, any of the lying days actually work.

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Lion and Unicorn II. - Back to the Logic Problems

Alice came across a lion and a unicorn in a forest of forgetfulness. Those two are strange beings. The lion lies every Monday, Tuesday and Wednesday and the other days he speaks the truth. The unicorn lies on Thursdays, Fridays and Saturdays, however the other days of the week he speaks the truth.

Lion said: Yesterday I was lying and two days after tomorrow I will be lying again.

Which day did he say that?

Okay. The answer to this riddle is actually quite simple if you really think about it. The solution is Thursday. The lion says "Yesterday I was lying and two days after tomorrow I will be lying again." It says the lion lies every Monday, Tuesday and Wednesday and every other day he speaks the truth. Okay...let's break it down for all of you. Yesterday is Wednesday. The lion was lying on Wednesday. And then two days AFTER tomorrow he will be lying again. So Tomorrow being Friday...add two days (Saturday and then Sunday)...leaves Monday. The solution to the question "Which day did he say that?" is Thursday.

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And then two days AFTER tomorrow he will be lying again. So Tomorrow being Friday...add two days (Saturday and then Sunday)...leaves Monday. The solution to the question "Which day did he say that?" is Thursday.

This is incorrect. Two days after tomorrow (assuming Thursday) is Sunday, not Monday...

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The answer has to be monday.

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The person who came up with the solution for this is WRONG!!!

The lion lies every Monday, Tuesday and Wednesday and the other days he speaks the truth.

Lion said: Yesterday I was lying and two days after tomorrow I will be lying again.

People are expecting the lion to be telling the truth in this statement, when in fact, the only way to make the statement true, is to assuse that what the Lion is NOT speaking the truth. (Take everything the Lion says to mean the opposite.)

The answer is Monday

He was actually speaking the truth yesterday (Sunday) as well two days after tomorrow(two days after Tomorrow [tomorrow being Tuesday] is Thursday), therefore.... Today is Monday, a day that the Lion lies!

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I would say Monday too, we need a specific day for the answer.

However, Why does the puzzle include a Unicorn as he plays no part.

I think I more interesting question would be:

Which day did the lion say this, and did the Unicorn agree with the lions statement?

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i'm surprised that no one considered the semantic argument... when we are informed that the lion lies on monday, tuesday, and wednesday, we cannot be certain this fact describes a propensity toward fibbing, as all here have assumed, or merely a state of recumbency. homonyms, anyone?

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The correct answer can only be Monday, especially when considering the laws of logic (I took a class on this, so hopefully I would know. The concept that the statement is only considered true when all parts of it are true (A ^ B.) is only accurate on a day when the lion is only telling the truth. This is because we assume that on a day when the lion is telling truth, A means A. However, on a day when the lion is only telling a lie (or the opposite of the truth), then we must assume that A actually means ~A (not A). So whereas on a truth day we are looking for both A and B to be true (A ^ B.), on a lying day we are in reality looking for everything to be NOT the truth, therefore we are actually looking for (~A ^ ~B.) to be true. This is only fulfilled on a Monday. (A ^ B.) is never fulfilled, so the only possible day is Monday.

Monday

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I agree with rookie1ja, I think a statement is false as long as one part of the statement is false, however if it was said in two different sentences then the only answer could be monday.

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I am agreeing with the answer being Monday. I may not have a big long drawn out answer from logic classes with A's and B's and stuff. But the lion has to say this statement on a day he lies. "Yesterday, i lied and two days after tomorrow I will lie again." Yesterday (being Sunday, which he speaks the truth) so lying fits (because it's Monday) and then two days after tomorrow (which is Thursday, a day he tells the truth) "I will lie again" is also a lie.

And I think they throw in a unicorn and days he lies and tells the truth to throw the people off because they will look to deeply into trying to get the answer. The question was only about what day the lion said the statement, which clearly has nothing to do with the Unicorn.

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It looks like Monday is the correct solution but it isn't.

I have to agree with rookie1ja.

The lion said the phrase in one sentence. It mean that he can say that sentence on a Tuesday.

Example:

Consider me a liar.

I didn't eat the pig yesterday infact i'm eating it right now.

In reality I'm not eating a pig right now so it means that the sentence is false.

Does this means that I eat a pig yesterday ????!!!!

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My head says any lying day; my heart says Monday.

What does the unicorn have to do with this?

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the answer HAS to be monday because if it was tuesday and he said "i was lying yesterday" then he would be telling the truth (because monday is a lying day) and he does not tell the truth on tuesdays.

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I don't think lion's is speaking in logic terms when he answer. The "AND" is not a logic statement. If it is one logic statement, there are 4 possible outcome and than you are right

True AND True = TRUE (truth days)

True AND False = FALSE (Lie days)

False AND True = FALSE (Lie days)

False AND False = FALSE (Lie days)

but the "and" in his statement is for connection only. So he made two statement in his sentence. And there are only 2 possible outcome instead of 4

True AND True = TRUE (truth days)

True AND False = Unacceptable

False AND True = Unacceptable

False AND False = FALSE (Lie days)

because he can only made one type of statement, there are two unacceptable outcome.

"I lie yesterday" Truth statement (TRUE) on Thuresday, Lie statement (FALSE) on Monday. Unacceptable on any other days because it will be telling the truth on a lie day and lie on a truth day.

"two days after tomorrow I will be lying again" Truth statement (TRUE) on Friday, Lie statement (FALSE) on Monday and Tuesday also if you disregard the "again".

So the answer is only possible on Monday.

I cut out using the INV to make it easier to understand. And if you want the real logic equations, it should be like this.

Truth days

"Statement 1" AND "Statement 2"

Lie days

INV(Statement 1) AND INV(Statement 2)

and the result must be TRUE.

in this case a truth statement is always TRUE and a Lie statement is always FALSE.

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Has to be Monday.

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I'd go with MONDAY on this one, but with this caveat: I don't see the need to solve every logic problem with a "prescribed formula" that was proferred by some textbook. Arguing the validity of a statement over the definition or the "logical function" of the word "and" simply eliminates creativity and thinking, reducing the solution to the application of a formula. It seems more fun to solve the puzzle in everyday english using common sense. I'm not trying to rant, just thinking freely

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your logic is right ...but still i would go with Monday as the answer...it says da lion lies on monday so i am assuming that both the statements it speaks are lies.

ANd ya, rookie1ja ...ur puzzles are damn good...keep up da great job

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How could the lion and unjicorn remember that? there in the forest of forgetfulness!