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Lion and Unicorn II.


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#41 lulu1221

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Posted 26 March 2008 - 10:49 PM

the lion lies on mon-wed and the rest of the week he tells the truth. His statement has two parts. The first one says he was "lying yesterday" which means that he would need to have said it on Thursday, the second says he will be lying again "two days after tomorrow" since he said it on Thursday then he would be lying again on Sunday and Sunday is not a lying day. Therefore, the statement is not true and he must have said it on Monday, Tuesday or Wednesday. ;)

I tried to explain it as clear as I could, sorry if I just made it more confusing :)
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#42 Jules McWyrm

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Posted 27 March 2008 - 04:43 PM

Wow - hot damn, people.

Logical conjunction is well defined. It doesn't matter what you imagine it to mean. All this opining on the definition of "AND" makes no more sense than arguing about the meaning of addition. Get over it.

Beyond grasping basic logical connectives, maybe read up on DeMorgan's Law, as well.

It's really simple.

A: the Lion was lying yesterday.
B: the Lion will be lying three days from now.

The Lion made the statment "A /\ B". That statment is NEVER TRUE. So it is always false. So the lion could make that statment on any day he was lying. Simple as that.

Applying DeMorgan's Law, we start with the original statment (A /\ B), negate it ( ~(A/\B) ), and convert it by applying the law ( ~A\/~B ). The lion can make this statment on any day that (~A\/~B) evaluates to TRUE.
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#43 cinnimini

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Posted 10 April 2008 - 06:01 PM

the day the music died ooorrrr monday
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#44 Malfure

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Posted 23 April 2008 - 11:15 PM

monday
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#45 Vishmi

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Posted 24 April 2008 - 07:04 AM

The answer should be Monday
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#46 Vishmi

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Posted 24 April 2008 - 07:15 AM

On second thoughts I think this statement can be made on a Monday, Tuesday or a Wednesday. Because this statement can be false if one is true and the other one is false or if both are false.

Edited by Vishmi, 24 April 2008 - 07:19 AM.

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#47 wow213

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Posted 03 May 2008 - 12:53 PM

did any1 notice 'forrest of forgetfullness'
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#48 boen

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Posted 21 May 2008 - 09:56 PM

... as you say, Lion made a joke on Monday, or Tuesday or Wednesday,
or, as Larryhl says, it can also be Thursday (if two days after tomorrow is Monday),
or I forgot about "Forest of forgetfullness"?

Edited by boen, 21 May 2008 - 10:00 PM.

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#49 mikedotcom

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Posted 23 June 2008 - 05:11 PM

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?


Spoiler for Solution

Spoiler for but then...

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#50 dreinick

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Posted 09 July 2008 - 07:05 AM

The answer has to be monday.



just because both halfs of the sentence are true does not make it the only answer.
if it were tuesday then half of the sentence would be false making the whole derivation false.
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