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Alexey
  • Member for 9 years, 7 months
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16 votes
1 answer
408 views

Can compacts on a real line behave "paradoxically" with respect to unions, intersections, and translation? What about other topological groups?

13 votes
4 answers
2k views

Topological characterization of the closed interval $[0, 1]$.

9 votes
4 answers
237 views

"Natural" proof of $P\left(\frac{d}{dx}\right)\bigl(e^{xy}Q(x)\bigr)=Q\left(\frac{d}{dy}\right)\bigl(e^{xy}P(y)\bigr)$.

8 votes
1 answer
260 views

Intuition behind the injectivity part of Hurewicz Theorem

6 votes
1 answer
182 views

In what kind of rings a divisor of a product is a product of divisors?

5 votes
0 answers
200 views

Category theoretic definition of a "rank" of a subset of an algebraic structure

4 votes
2 answers
418 views

An example of a monomorphism that is not an equalizer in "Abstract and Concrete Categories -- The Joy of Cats"

4 votes
2 answers
644 views

"Canonical" symmetrization/skew-symmetrization/alternation of multilinear functions

4 votes
0 answers
4k views

What are sliding vectors mathematically?

4 votes
1 answer
202 views

"Pivot step" that Donald Knuth mentioned in TAOCP

3 votes
0 answers
228 views

Monads in monoids

3 votes
0 answers
52 views

Apparent (minor) error in Cauchy's article on pressure or tension in a solid body

3 votes
1 answer
176 views

Simplicial complexes of linear independencies

3 votes
1 answer
156 views

"Adjugate" of an endomorphism of a finite-rank free module

3 votes
1 answer
870 views

If two points in a space are connected by a path, is there an injective map of an interval?

3 votes
2 answers
544 views

Gödel's incompleteness theorems: where to learn? Is there a straightforward relation between the two?

2 votes
2 answers
333 views

A problem with lambda calculus notation and semantics for function-valued functions

2 votes
1 answer
68 views

Some weaker axiom than "no nontrivial zero divisors."

2 votes
1 answer
234 views

Is there a recommended symbol for "equal by abuse of notation"?

2 votes
1 answer
461 views

Most general definition of a normal vector to an affine subspace of a Euclidian space

2 votes
1 answer
238 views

Textbooks that use notation with explicit argument variable in the upper bound $\int^x$ for "indefinite integrals."

2 votes
1 answer
887 views

Notation for juxtaposition operation on matrices

2 votes
2 answers
53 views

Term for elements of a monoid in a corresponding monid ring

2 votes
0 answers
36 views

How to call the scalar "curl" of a vector field in a plane?

2 votes
1 answer
52 views

A simple example of a $G$-principal bundle that cannot be lifted to an $F$-principal bundle along an epimorphism $F\to G$.

1 vote
1 answer
36 views

Are coslice categories of preadditive categories preadditive?

1 vote
0 answers
26 views

Relationship between modulus (absolute value) and algebraic norm.

1 vote
0 answers
11 views

Classification of analytic involutions

1 vote
0 answers
140 views

Goldbach-like and Collatz-like conjectures and theorems

1 vote
0 answers
35 views

Notation for equivalence relations between pairs of numbers that have the same difference or the same quotient