Author: Antonio Dmaz Ramos
Title: A family of acyclic functors
Abstract: We describe the projectives in the category of functors from a
DCC poset to abelian groups. Based on this description we define a related
condition, pseudo-projectivity, and we prove that this condition is enough
for the vanishing of the derived direct limits. We apply this result to
deduce a generalized version of Whitehead^Rs theorem for the pushout. The
dual results for inverse limits are also considered.