Which Sentences Are Lying About Exclamation Marks?

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Discussion Overview

The discussion revolves around the truth values of three sentences that involve exclamation marks and their implications. Participants explore logical contradictions, the nature of truth in propositions, and the potential for multiple interpretations regarding the sentences' truthfulness.

Discussion Character

  • Debate/contested
  • Mathematical reasoning
  • Conceptual clarification

Main Points Raised

  • Some participants argue that sentence A contradicts itself, leading to the conclusion that it must be false, which implies that B is true and C is false.
  • Others propose that A and B could both be truthful if the sentences that end with periods are the ones that are lying.
  • A participant notes that the law of excluded middle and law of non-contradiction apply, suggesting that A cannot be true without leading to inconsistency.
  • Another viewpoint suggests that there are three possibilities regarding the truth of sentences with exclamation marks: all are lying, all are truthful, or some are lying while others are truthful.
  • One participant emphasizes that B correctly identifies A as a lie, while C is deemed false because B is true.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the truth values of the sentences, and the discussion remains unresolved with no consensus on a definitive interpretation.

Contextual Notes

Participants highlight the complexity of assigning truth values to the sentences, noting potential inconsistencies and the limitations of classical logic in this context.

Who May Find This Useful

Readers interested in logic, paradoxes, and the philosophy of language may find this discussion relevant.

some_one
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data:

A.each sentence which ends with exclamation mark is lying!
B.sentence A is lying!
C.sentence B is lying.

which claim is wright regarding these sentences?
1.A and C are truthful and B is lying
2.C is truthful while A and B are lying
3. B is truthful while A and C are lying
4.C is lying while A and B are truthfulthat exclamation mark thing makes me confused
sentence A contradicts itself
 
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some_one said:
data:

A.each sentence which ends with exclamation mark is lying!
B.sentence A is lying!
C.sentence B is lying.

which claim is wright regarding these sentences?
1.A and C are truthful and B is lying
2.C is truthful while A and B are lying
3. B is truthful while A and C are lying
4.C is lying while A and B are truthful


that exclamation mark thing makes me confused
sentence A contradicts itself

A and B can both be truthful if it is really sentences that end in period that are lying.
 
3. B is truthful while A and C are lying

A contradicts itself if assumed to be true. The only way to avoid the contradiction is to assume it is false. Therefore, B is true, and C is false.
 
a period meens nothing

how did come to this answer
how did you solve this exclamation mark thing??
 
A proposition is either true or false, bot nut both (law of excluded middle + law of non-contradiction). The question clearly suggests that there is a way to assign truth values to the propositions without creating any inconsistency. Proposition A is either true or false. If we assume it is true, we obtain the following:

a. Sentence A is true.
b. Sentence A is a sentence which ends with an exclamation mark.

c. Therefore sentence A is false.

This is inconsistent; we have obtained both the statements "sentence A is true" and "sentence A is false" from the assumption that A is true. Therefore sentence A is not true. Therefore, it must be false. That said, we are forced to accept that B is true, and then that C is false.

To be noted: some propositions are not classifiable as either true or false, this being perhaps the biggest failure of classic Aristotelian logic. For example, the sentence "This sentence is false." leads to a contradiction whether we assume it is true or false. However, like I said, the question suggests that there is a way to assign truth values without contradictions, and so you may assume the laws of classical logic can be applied.
 
some_one said:
that exclamation mark thing makes me confused
sentence A contradicts itself

There are 3 possibilities:

1. All sentences that end in an exclamation mark are lying.
2. All sentences that end in an exclamation mark are truthful.
3. Some sentences that end in a "!" are lying, and some are truthful.

The trick here is that many people do not think of or consider possibility #3.
 
some_one said:
a period meens nothing

how did come to this answer
how did you solve this exclamation mark thing??

You're right, I meant to say that A was internally consistent with a lie if such was the case, because in saying that exclamation marks are lies - that is a lie. It doesn't mean all exclamation mark sentences are lies however.

B in calling A a lie is merely making a correct observation.

And C of course is a lie because B is True.
 
thanks i understand this question now
 

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