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Daniel Teixeira
  • Member for 4 years, 7 months
  • Last seen more than a month ago
6 votes

How to prove $f(x)=a$ is a subspace

5 votes

Pullback in the category of graphs

4 votes
Accepted

Flaw in a proof of uniqueness of products in a category?

4 votes
Accepted

Monoidal category: Inequivalent associators

3 votes

The set of all vector spaces

3 votes

$x-y> 1$. How is this relation neither symmetric nor anti symmetric?

3 votes

Using a smooth function to replace a coordinate on a manifold

3 votes

Universal property for tensor product in an arbitrary category

3 votes

Monomorphisms of monoids

2 votes

What is the union of two varieties

2 votes

Can the starting point of an infinite series be a non-integer?

2 votes

Is X a cover of itself?

2 votes

Rationalize this

2 votes

Why are the coefficients always equal?

2 votes

Tensor and Wedge

2 votes
Accepted

Let $U, V \in M_{n\times n}$ be orthogonal matrices. Explain why $UV$ is an orthogonal matrix

2 votes
Accepted

Define the fact that $Hom_{C}(X,Y)$ is bijective for category $C.$

1 vote
Accepted

Is there an $\infty$-category of spaces?

1 vote
Accepted

Skeletal categories and isomorphisms between an object and itself

1 vote

The set of self-adjoint maps $P$ with $P^2=P$ and rank $k$ is a submanifold

1 vote
Accepted

Dual of a statement involving adjoint functors

1 vote
Accepted

How to find the generators of a principal Ideal?

1 vote

Differentiating a convergent power series with "missing terms"

1 vote

Manifold with Atlases of different Dimension

1 vote

Why are the fibers of principal G-bundles homeomorphic to G?

1 vote
Accepted

Well Defined Maps

1 vote

Isomorphism method

1 vote
Accepted

Field of polynomials and field of fractions

1 vote

Universal Cover of $SO^+(2,4)$

1 vote

Concretely, what is the horn $\Lambda_k^n$?