The Two-Square Lemma and the connecting morphism
Category Theory
2011-03-29 v1
Abstract
We obtain a generalization of the Two-Square Lemma proved for abelian categories by Fay, Hardie, and Hilton in 1989 and (in a special case) for preabelian categories by Generalov in 1994. We also prove the equivalence up to sign of two definitions of a connecting morphism of the Snake Lemma.
Cite
@article{arxiv.1103.5251,
title = {The Two-Square Lemma and the connecting morphism},
author = {Yaroslav Kopylov},
journal= {arXiv preprint arXiv:1103.5251},
year = {2011}
}
Comments
10 pages