Zeeman's comparison theorem
In homological algebra, Zeeman's comparison theorem, introduced by Christopher Zeeman, gives conditions for a morphism of spectral sequences to be an isomorphism. == Statement == == Illustrative example == As an illustration, we sketch the proof of Borel's theorem, which says the cohomology ring of a classifying space is a polynomial ring.
Source: Wikipedia — Zeeman's comparison theorem (CC BY-SA 4.0)