Documentation

Mathlib.Algebra.Homology.HomotopyCategory.HomologicalFunctor

The homological functor

In this file, it is shown that if C is an abelian category, then homologyFunctor C (ComplexShape.up ℤ) n is a homological functor HomotopyCategory C (ComplexShape.up ℤ) ⥤ C. As distinguished triangles in the homotopy category can be characterized in terms of degreewise split short exact sequences of cochain complexes, this follows from the homology sequence of a short exact sequences of homological complexes.