Derived Functor SemiExt
Let A be an exact category in which all infinite products exist and the functors of infinite product are exact. A complex C• over A is called Italic if it belongs to the minimal triangulated subcategory Acycl ctr (A) of the homotopy category Hot(A) containing all the total complexes of exact triples ′K• → K• → ″K• of complexes over A and closed under infinite products. Any contraacyclic complex is acyclic. It follows from the next lemma that any acyclic complex bounded from above is contraacyclic.
KeywordsFull Subcategory Abelian Category Total Complex Arbitrary Complex Triangulate Category
Unable to display preview. Download preview PDF.