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4 votes
3 answers
4k views

Is the Cantor Pairing function guaranteed to generate a unique real number for all real numbers?

I recently learned that for natural numbers, the Cantor Pairing function allows one to output a unique natural number from any combination of two natural numbers. According to wikipedia, it is a ...
Devin King's user avatar
0 votes
0 answers
60 views

Find the closest/next $x\in\mathbb{N}$ that satisfies the equation $Ⲭ_{\mathbb{N}}(f(x)) = 1$.

Find the closest/next $x\in\mathbb{N}$ that satisfies the equation $Ⲭ_ℕ(f(x)) = 1$, where $Ⲭ_\mathbb{N}(x): \mathbb{R} \rightarrow \mathbb{N}$ is defined by $$ \begin{cases} 1 &\text{if } f(x) \...
TRH's user avatar
  • 1
1 vote
1 answer
34 views

How to prove $2^{\sqrt{f(n)}} \in O\ (2^{f(n)})$ if $f:\Bbb{N}\rightarrow \Bbb{R^+}$?

How to prove $2^{\sqrt{f(n)}} \in O\ (2^{f(n)})$ if $f:\Bbb{N}\rightarrow \Bbb{R^+}$? So we want to prove $\exists c\in\Bbb{R^+}:\ [\exists B\in\Bbb{N}:[\ \forall n\in\Bbb{N}:\ n\ge B\rightarrow 2^{\...
CoolKid's user avatar
  • 2,756