Snake lemma for sheaves of abelian groups
25064
Proving the snake lemma without a diagram chase
7708
Obstruction to the splitness of an exact sequence of holomorphic vector bundles
99671
Are surjective sheaf morphisms locally surjective?
82310
Epimorphisms from a free group onto a free group
68128
Two term free resolution of an abelian group.
123130
Showing an isomorphism between exterior products of a free module
96380
Representation of $\text{sl}(2,\mathbb{C})$
76432
$i^{-1} F$ a sheaf if and only if $\varinjlim_{ U \subseteq X \text{ open}, ~ x,y \in U } F(U) \to F_x \times F_y$ is an isomorphism.
60111
On the converse of Schur's Lemma
81762
Colimits in that category of short exact sequences of abelian groups
61674
Coker of powers of an endomorphism
74617
Equivalent conditions for a preabelian category to be abelian
137512
cup product in cohomology ring of a suspension
141843
n-dimensional vector space isomorphic to the n-th product of a field as abelian groups
43863
Question about left exactness of the section functor for sheaves
74445
Noetherian and Artinian modules
65873
A proof for Atiyah-Macdonald Exercise I.21.iii