Mayer–Vietoris sequence
= Mayer–Vietoris sequence
{wiki=Mayer–Vietoris_sequence}
The Mayer–Vietoris sequence is a fundamental tool in algebraic topology, particularly in the study of singular homology and cohomology theories. It provides a way to compute the homology or cohomology of a topological space from that of simpler subspaces.