Self-Consistency of Sequence of Statements: Which is True?

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In summary, the sequence of statements is consistent for any $n$, but at least 1 of the statements is false.
  • #1
TheBigBadBen
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Consider the following sequence of statements:
$$
S_1: \text{at least 1 of the statements }S_1-S_n \text{ is false}\\
S_2: \text{at least 2 of the statements }S_1-S_n \text{ are false}\\
\vdots \\
S_n: \text{at least } n \text{ of the statements }S_1-S_n \text{ are false}
$$
Where $n$ is some integer.

Question: for which $n$ are these statements self-consistent? In those cases: what is the truth value of each statement?

I got this off of a blog I tend to frequent. I will wait before posting the solution this time.

EDIT:
Changed the question; I had written the statements wrong
 
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  • #2
Suppose $k$ out of $n$ statements are true.
Then $S_1$ up to $S_k$ have to be true and the rest has to be false.
This appears to be consistent for any $n$ and any $0\le k \le n$.
 
  • #3
I like Serena said:
Suppose $k$ out of $n$ statements are true.
Then $S_1$ up to $S_k$ have to be true and the rest has to be false.
This appears to be consistent for any $n$ and any $0\le k \le n$.

Sorry about that, you were absolutely right about the question as phrased.

However, this new version should prove to be a bit more interesting. This is what I had meant; I had accidentally written "true" instead of "false".
 
  • #4
If $S_n$ is true, then $n$ statements are false, including $S_n$.
Therefore $S_n$ is false.

We now know that at least $1$ statement is false.
Therefore $S_1$ is true.
For $n=1$ this is a contradiction, and for $n=2$ this is a consistent solution.

For $n \ge 3$ we can say, that if $S_{n-1}$ were true, then $n-1$ statements are false.
Since $S_1$ is true, this implies that $S_{n-1}$ is false.
Therefore $S_{n-1}$ is false.

So at least $2$ statements are false.
Therefore $S_2$ is true.
For $n=3$ this is a contradiction, and for $n=4$ this is a consistent solution.

Etcetera.In other words, we get a consistent consistent solution if and only if $n$ is even.
In that case $S_1$ up to $S_{n/2}$ are true and $S_{n/2+1}$ up to $S_{n}$ are false. $\qquad \blacksquare$
 
  • #5
I like Serena said:
If $S_n$ is true, then $n$ statements are false, including $S_n$.
Therefore $S_n$ is false.

We now know that at least $1$ statement is false.
Therefore $S_1$ is true.
For $n=1$ this is a contradiction, and for $n=2$ this is a consistent solution.

For $n \ge 3$ we can say, that if $S_{n-1}$ were true, then $n-1$ statements are false.
Since $S_1$ is true, this implies that $S_{n-1}$ is false.
Therefore $S_{n-1}$ is false.

So at least $2$ statements are false.
Therefore $S_2$ is true.
For $n=3$ this is a contradiction, and for $n=4$ this is a consistent solution.

Etcetera.In other words, we get a consistent consistent solution if and only if $n$ is even.
In that case $S_1$ up to $S_{n/2}$ are true and $S_{n/2+1}$ up to $S_{n}$ are false. $\qquad \blacksquare$

Couldn't have phrased it better myself.

The source, for anybody interested:
The Parity Paradox – Futility Closet

I highly recommend the website as a time-wasting tool.
 

FAQ: Self-Consistency of Sequence of Statements: Which is True?

What is meant by self-consistency of sequence of statements?

Self-consistency of sequence of statements refers to the logical coherence and consistency of a series of statements or propositions. It means that the statements do not contradict each other and together form a logical and valid argument.

Why is self-consistency important in science?

Self-consistency is crucial in science because it ensures that the conclusions drawn from a series of statements are sound and reliable. It helps to avoid logical fallacies and ensures that the scientific method is followed properly.

Can a sequence of statements be self-consistent but still be false?

Yes, a sequence of statements can be self-consistent but still be false. This can happen when the statements are based on incorrect assumptions or data. Self-consistency does not guarantee the truthfulness of a statement, only its logical coherence.

How do scientists ensure self-consistency in their research?

Scientists ensure self-consistency in their research by carefully examining and evaluating their data and methods. They also use peer review and replication to check for any inconsistencies or errors in their findings.

What are some common challenges to maintaining self-consistency in scientific studies?

Some common challenges to maintaining self-consistency in scientific studies include biased or incomplete data, confirmation bias, and limitations in technology or resources. Additionally, complex or abstract concepts can also make it difficult to ensure self-consistency in scientific studies.

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