List questions from proof-writing

Published on 13 Apr 2026 - 23:26

175

Views

Category theory: ex. 3.3.vi from Riehl's "Category Theory in Context"

Published on 16 Apr 2026 - 8:42

373

Views

How to Understand proof by contradiction.

Published on 09 Apr 2026 - 14:04

619

Views

Any vector in the Null space of a matrix A is orthogonal to any vector in the Row space of A

Published on 15 Apr 2026 - 0:03

282

Views

$\sigma$-fields can not be countably infinite

Published on 12 Apr 2026 - 18:21

337

Views

Proving the Product of topological spaces are metrizable

Published on 12 Apr 2026 - 4:42

234

Views

Any subcollection $\mathcal A_1$ of a locally finite collection $\mathcal A$ of subsets of $X$ is locally finite.

Published on 13 Apr 2026 - 20:58

2.2k

Views

If $f'(x)\not = 1$ for all real numbers $x$, then $f$ has at most one fixed point

Published on 15 Apr 2026 - 17:59

172

Views

Verifying an inner product

Published on 13 Apr 2026 - 22:30

45

Views

Repunits and Goormaghtigh's conjecture

Published on 15 Apr 2026 - 13:09

1.6k

Views

Can any proof by contrapositive be rephrased into a proof by contradiction?

Published on 12 Apr 2026 - 5:38

173

Views

The application $\mu^*$ is an outer measure. A proof without the Fubin's Theorem.

Published on 11 Apr 2026 - 10:07

3.8k

Views

Show that $\gcd(a, 0)$ exists and equals $|a|$ for all $a$ in $\mathbb Z$

Published on 12 Apr 2026 - 22:55

202

Views

How to prove: Two solutions to pairwise known distances transformed either by rotation+translation or reflection+translation?

Published on 16 Apr 2026 - 6:50

354

Views

Verifying a proof regarding the duals of two equivalent compound propositions also being equivalent

Published on 24 Apr 2026 - 1:07

List Question

Proving set identities: empty set case.

Category theory: ex. 3.3.vi from Riehl's "Category Theory in Context"

How to Understand proof by contradiction.

Any vector in the Null space of a matrix A is orthogonal to any vector in the Row space of A

$\sigma$-fields can not be countably infinite

Proving the Product of topological spaces are metrizable

Any subcollection $\mathcal A_1$ of a locally finite collection $\mathcal A$ of subsets of $X$ is locally finite.

If $f'(x)\not = 1$ for all real numbers $x$, then $f$ has at most one fixed point

Verifying an inner product

Repunits and Goormaghtigh's conjecture

Can any proof by contrapositive be rephrased into a proof by contradiction?

The application $\mu^*$ is an outer measure. A proof without the Fubin's Theorem.

Show that $\gcd(a, 0)$ exists and equals $|a|$ for all $a$ in $\mathbb Z$

How to prove: Two solutions to pairwise known distances transformed either by rotation+translation or reflection+translation?

Verifying a proof regarding the duals of two equivalent compound propositions also being equivalent

Trending Questions

Popular # Hahtags

Popular Questions