chain complex
in homological algebra, a structure consisting of a sequence of modules and a sequence of homomorphisms between consecutive modules such that the image of each homomorphism is included in the kernel of the next
perverse sheaf
bounded cochain complex C of constructible sheaves over a topological space, such that, for all integers i, the support of ℋ⁻ⁱ(C) has dimension at most 2i, and similarly for the dual complex of C, where ℋ denotes the cohomology sheaf
exact sequence
sequence of homomorphisms such that each kernel equals the preceding image
differential graded module
Z-graded module with a compatible differential