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Jhon Doe

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Wanna get better at math

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Top Questions

Subset of totally bounded set is totally bounded.

general-topology elementary-set-theory asked Feb 26, 2018 at 3:27

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$\mathbb{Q}(\alpha)=\mathbb{Q}(\beta)$ if $\alpha, \beta$ are algebraic over $\mathbb{Q}$ of degree $2$ and $\alpha +\beta$ is a root of a quadratic.

polynomials field-theory galois-theory roots extension-field asked Oct 15, 2018 at 13:59

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If $ U$ is maximal among non-principal ideals show that $U$ is prime. (Hints?)

ring-theory commutative-algebra maximal-and-prime-ideals asked Mar 3, 2018 at 4:03

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Proof of Uncountable Basis for $\mathbb{N} \to \mathbb{R}$ over $\mathbb{R}$

linear-algebra set-theory asked Feb 12, 2017 at 14:13

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Counter-example: If $J$ is prime then $f^{-1} (J) $ is prime. $f$ need not be unital.

abstract-algebra maximal-and-prime-ideals ring-homomorphism asked Feb 17, 2018 at 17:05

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Prove that no ordinal is an element of itself

set-theory ordinals well-orders asked Nov 6, 2017 at 0:03

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Does a field extension $L$ of $F$ have the same characteristic as $F$?

abstract-algebra proof-verification galois-extensions asked Oct 1, 2018 at 9:09

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Addition of continuous functions over topological spaces is continuous.

general-topology proof-verification continuity asked Apr 16, 2019 at 14:22

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Limit of sequence of Riemann integrable functions is not Riemann integrable.

real-analysis integration riemann-integration asked Aug 30, 2020 at 9:03

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If $(X_n)_{n\in \mathbb{N}}$ is a martingale s.t. $\sup_n E[|X_n|]\leq M < \infty$, then $\sum_{n\geq 2}(X_n-X_{n-1})^2<\infty$ almost surely.

probability-theory measure-theory conditional-probability martingales asked Feb 23, 2021 at 11:13

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