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

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The discussion centers on the self-consistency of a sequence of statements, where each statement asserts a certain number of preceding statements are false. It concludes that a consistent solution exists only when the integer n is even. For even n, the first half of the statements are true while the latter half are false. In contrast, for odd n, contradictions arise, making self-consistency impossible. The analysis highlights the relationship between the parity of n and the truth values of the statements.
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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
 
Last edited:
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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 $0\le k \le n$.
 
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".
 
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. $\qquad \blacksquare$
 
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.
 
Here is a little puzzle from the book 100 Geometric Games by Pierre Berloquin. The side of a small square is one meter long and the side of a larger square one and a half meters long. One vertex of the large square is at the center of the small square. The side of the large square cuts two sides of the small square into one- third parts and two-thirds parts. What is the area where the squares overlap?

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