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Mar 1, 2014 at 22:56 vote accept barak manos
Feb 27, 2014 at 14:46 comment added GH from MO @barak: The "$n$-th prime number" has a short formal definition within set theory (ZFC), it is a translation of the usual definition "in words". In fact any recursive function can be represented by a first order formula within Peano arithmetic.
Feb 27, 2014 at 12:15 comment added barak manos @GH from MO: Well I kinda meant mathematical symbols (though I'm not sure how to express this meaning in a "mathematical notion").
Feb 27, 2014 at 10:46 comment added GH from MO It is easy to define $P_n$ with a few symbols: $P_n$ is the $n$-th prime number.
Feb 27, 2014 at 10:25 comment added barak manos @Pietro Majer, thanks... either way, what I meant is a range between two "finitely defined" functions $f(n)$ and $g(n)$. Can you define $P_n$ in a finite "amount of paper"?
Feb 27, 2014 at 10:23 comment added Pietro Majer Actually I really meant $f(n)=g(n)=p_n$.
Feb 27, 2014 at 9:04 comment added barak manos @Pietro Majer: Oh, I understand now, you mean $f(n)=P_{n}$ and $g(n)=P_{n+1}$?
Feb 27, 2014 at 9:00 comment added Pietro Majer Then maybe your problem is : the function $f$ being ${\it given}$, ${\it find}$ the smallest function $g\ge f$ such that there is a prime in the interval? I was just saying that if we can choose both $f$ and $g$ there is the trivial answer above.
Feb 27, 2014 at 8:55 comment added barak manos It will not describe my question properly if I do so. Please note that I'm asking if there is a prime number between $n^2$ and $(n+1)^2$. How can $f(n)$ be $n$ in this case?
Feb 27, 2014 at 8:53 comment added Pietro Majer I think it is more clear if you fix $f$ to be the identity, $f(n)=n$ (besides, taking $f(n)=g(n)=p_n$ would somehow trivialize the question)
Feb 27, 2014 at 8:43 answer added user9072 timeline score: 6
Feb 27, 2014 at 8:25 answer added GH from MO timeline score: 7
Feb 27, 2014 at 8:04 history edited barak manos CC BY-SA 3.0
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Feb 27, 2014 at 7:58 history asked barak manos CC BY-SA 3.0