New posts in category-theory

Solutions to questions in "Categories for the Working Mathematician"

Wedge sum of spheres is the quotient $X^n/X^{n-1}$

Products and coproducts in the simplex category

What is meant by a "structure map"?

Universal skew field of fractions

Non-trivial natural endomorphisms on $\operatorname{Top}$

Tannakian theory for Lie algebras

Showing a Functor is not Representable

Definition of diffeological space

Meaning of pullback

Identify the universal property of kernels

Is there a universal property for the ultraproduct?

Category Theory textbook (learning through guided discovery Dummit and Foote)

Trying to understand significance of monoid as a one object category

Does free functor preserve monomorphism?

Simple objects with isomorphic projective covers

Can a free group over a set be constructed this way (without equivalence classes of words)?

Simple example of product not preserving coequaliser in $\mathbf{Top}$

Why is the limit the product, but not the coproduct?

Category theory text that defines composition backwards?