User Zzz

20 votes

1 answer

6k views

Proof that product topology of subspace is same as induced product topology

general-topology proof-verification

asked Nov 27, 2015 at 10:36

7 votes

2 answers

4k views

Continuity of cartesian product of functions between topological spaces

asked Feb 26, 2016 at 11:54

0 votes

1 answer

3k views

Is epsilon a useless symbol and when epsilon does belong into CFL?

formal-languages

asked Feb 1, 2016 at 22:58

0 votes

2 answers

2k views

What are open subsets of half-open interval of $\mathbb{R}$?

general-topology

asked Oct 30, 2015 at 13:30

2 votes

1 answer

2k views

If $\gcd(a,b)=1$, then there exists integers $x$ and $y$ such that $xa + yb = 1$

abstract-algebra

asked Jul 29, 2015 at 0:43

6 votes

1 answer

1k views

Product space that is compact, but isn't sequentially compact

general-topology

asked Dec 3, 2015 at 17:52

-2 votes

1 answer

655 views

Sierpinski space question

general-topology

asked Sep 12, 2015 at 19:27

0 votes

2 answers

652 views

Open or closed mapping between closed disk and unit sphere

general-topology multivariable-calculus

asked Nov 16, 2015 at 21:28

2 votes

3 answers

585 views

If $X$ is compact metric space, then $X$ is bounded

general-topology

asked Oct 30, 2015 at 22:06

0 votes

2 answers

543 views

Quotient topology $\mathbb{R}/\sim $ where $x\sim y$ iff $x-y\in\mathbb{Z}$ [duplicate]

general-topology

asked Mar 15, 2016 at 19:55

0 votes

1 answer

425 views

Calculus of variations and Euler's equation

functional-analysis proof-explanation

asked Sep 27, 2016 at 10:56

1 vote

1 answer

423 views

Calculus of variations and Bernstein's theorem

functional-analysis proof-explanation

asked Sep 1, 2016 at 10:51

0 votes

1 answer

378 views

$f$ is homeomorphism iff $A\subseteq X$ open iff $f(A)\subseteq Y$ is open

general-topology

asked Nov 13, 2015 at 10:21

0 votes

1 answer

354 views

Increment of a functional and Taylor's theorem

functional-analysis proof-explanation

asked Jun 30, 2016 at 16:40

1 vote

1 answer

322 views

Definition of a neighborhood in normed linear space?

functional-analysis definition

asked Sep 26, 2016 at 18:33

0 votes

2 answers

321 views

What does $A^{B}$ mean? [duplicate]

elementary-set-theory notation

asked Jul 2, 2015 at 12:55

0 votes

3 answers

297 views

$(\omega +3)\cdot\omega=\omega\cdot\omega$ [duplicate]

set-theory book-recommendation ordinals

asked Jun 8, 2016 at 19:47

1 vote

2 answers

275 views

Continuous surjection from simple closed curve to unit circle

general-topology

asked Nov 21, 2015 at 20:27

0 votes

1 answer

253 views

Proof that standard translation of modal formula is equivalent to the FO formula

asked Apr 15, 2016 at 12:37

1 vote

4 answers

248 views

Every half-plane $H=\{(x,y)\in\mathbb{R}^{2}\mid ax+by+c\geq 0\}$ is connected

general-topology

asked Mar 10, 2016 at 20:23

0 votes

1 answer

229 views

Generated subframe of a frame

asked Apr 22, 2016 at 14:27

4 votes

3 answers

225 views

Last digit of $1238237^{18238456}$

elementary-number-theory

asked Jul 30, 2015 at 18:14

1 vote

1 answer

174 views

If $E\subseteq X$ is connected, $E\cap A\neq\emptyset$ and $E\cap(X\setminus A)\neq\emptyset$ then $E\cap\partial A\neq\emptyset$

general-topology proof-verification

asked Mar 10, 2016 at 9:05

1 vote

2 answers

128 views

Incomplete subspace of Banach space

functional-analysis proof-writing

asked Aug 26, 2016 at 14:23

0 votes

1 answer

127 views

Find an equivalent standard translation for FO formula

asked Apr 17, 2016 at 17:27

1 vote

1 answer

124 views

Define product topology for subspace

general-topology

asked Nov 26, 2015 at 22:41

2 votes

0 answers

123 views

Definition of extrema in calculus of variations

functional-analysis definition

asked Jun 26, 2016 at 12:06

1 vote

1 answer

118 views

Homeomorphism between $X/\tilde~$ and $Y/\tilde~'$

general-topology

asked Mar 15, 2016 at 17:45

1 vote

1 answer

115 views

Euler-Lagrange example proof

functional-analysis proof-verification euler-lagrange-equation

asked Sep 4, 2016 at 14:39

0 votes

0 answers

101 views

Sequence convergence in box topology

general-topology

asked Nov 24, 2015 at 20:32

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39 Questions

Proof that product topology of subspace is same as induced product topology

Continuity of cartesian product of functions between topological spaces

Is epsilon a useless symbol and when epsilon does belong into CFL?

What are open subsets of half-open interval of $\mathbb{R}$?

If $\gcd(a,b)=1$, then there exists integers $x$ and $y$ such that $xa + yb = 1$

Product space that is compact, but isn't sequentially compact

Sierpinski space question

Open or closed mapping between closed disk and unit sphere

If $X$ is compact metric space, then $X$ is bounded

Quotient topology $\mathbb{R}/\sim $ where $x\sim y$ iff $x-y\in\mathbb{Z}$ [duplicate]

Calculus of variations and Euler's equation

Calculus of variations and Bernstein's theorem

$f$ is homeomorphism iff $A\subseteq X$ open iff $f(A)\subseteq Y$ is open

Increment of a functional and Taylor's theorem

Definition of a neighborhood in normed linear space?

What does $A^{B}$ mean? [duplicate]

$(\omega +3)\cdot\omega=\omega\cdot\omega$ [duplicate]

Continuous surjection from simple closed curve to unit circle

Proof that standard translation of modal formula is equivalent to the FO formula

Every half-plane $H=\{(x,y)\in\mathbb{R}^{2}\mid ax+by+c\geq 0\}$ is connected

Generated subframe of a frame

Last digit of $1238237^{18238456}$

If $E\subseteq X$ is connected, $E\cap A\neq\emptyset$ and $E\cap(X\setminus A)\neq\emptyset$ then $E\cap\partial A\neq\emptyset$

Incomplete subspace of Banach space

Find an equivalent standard translation for FO formula

Define product topology for subspace

Definition of extrema in calculus of variations

Homeomorphism between $X/\tilde~$ and $Y/\tilde~'$

Euler-Lagrange example proof

Sequence convergence in box topology