List questions from examples-counterexamples

Published on 23 Apr 2026 - 17:43

260

Views

A variation on Giuga's conjecture

Published on 04 May 2026 - 2:11

219

Views

Has miscommunication ever benefited mathematics? Let's list examples.

Published on 05 May 2026 - 12:40

480

Views

A congruence involving Chebyshev polynomials

Published on 10 May 2026 - 10:24

211

Views

normal doesn't imply paracompact

Published on 02 May 2026 - 3:44

720

Views

Examples for $\max\{f(x)+g(x)\}\leq \max{f(x)}+ \max{g(x)}$ and $\min\{f(x)+g(x)\}\geq\min{f(x)}$+min{g(x)}.

Published on 29 Apr 2026 - 12:19

67

Views

Find $f$ and $g$ that are both $C^1$ with $f(y)=g(y)=0$ and $f'(y)= a g'(y) \neq 0$, but $\lim_{x\to y} \frac{f(x)}{g(x)}$ DNE.

Published on 29 Apr 2026 - 12:54

65

Views

Need an example of a category whose products are indexed by these sets.

Published on 29 Apr 2026 - 12:54

408

Views

Subset of $\Bbb R$ isomorphic to $\omega+\omega$ and another isomorphic to $\omega\times\omega$

Published on 10 May 2026 - 8:44

428

Views

Counterexamples showing natural density is not a measure

Published on 02 May 2026 - 5:17

289

Views

Counterexamples and Kolmogorov zero-one law (on the convergence of $\sum_{k=1}^\infty (\xi_k - \mathbf{E}(\xi_k))$)

Published on 29 Apr 2026 - 12:54

63

Views

towers of 2 and primes, generation s of big primes by iteration of the function $2^{x}$

Published on 10 May 2026 - 12:27

305

Views

A congruence involving Lucas polynomials

Published on 04 May 2026 - 2:12

1.3k

Views

What is an example of a pi-system that is not a sigma algebra?

Published on 29 Apr 2026 - 12:53

443

Views

Quasi-components in compact space

Published on 29 Apr 2026 - 12:54

List Question

Counter examples in modal logic

A variation on Giuga's conjecture

Has miscommunication ever benefited mathematics? Let's list examples.

A congruence involving Chebyshev polynomials

normal doesn't imply paracompact

Examples for $\max\{f(x)+g(x)\}\leq \max{f(x)}+ \max{g(x)}$ and $\min\{f(x)+g(x)\}\geq\min{f(x)}$+min{g(x)}.

Find $f$ and $g$ that are both $C^1$ with $f(y)=g(y)=0$ and $f'(y)= a g'(y) \neq 0$, but $\lim_{x\to y} \frac{f(x)}{g(x)}$ DNE.

Need an example of a category whose products are indexed by these sets.

Subset of $\Bbb R$ isomorphic to $\omega+\omega$ and another isomorphic to $\omega\times\omega$

Counterexamples showing natural density is not a measure

Counterexamples and Kolmogorov zero-one law (on the convergence of $\sum_{k=1}^\infty (\xi_k - \mathbf{E}(\xi_k))$)

towers of 2 and primes, generation s of big primes by iteration of the function $2^{x}$

A congruence involving Lucas polynomials

What is an example of a pi-system that is not a sigma algebra?

Quasi-components in compact space

Trending Questions

Popular # Hahtags

Popular Questions