Commit 2025-11-04 10:34 3148fe4a
View on Github →feat(RepresentationTheory/Homological/GroupHomology/Functoriality): the degree 1 part of the corestriction-coinflation exact sequence (#25969)
Given a G-representation A and a normal subgroup S of G, this PR defines the corestriction-coinflation short complex
H₁(S, A) ⟶ H₁(G, A) ⟶ H₁(G ⧸ S, A_S) induced by the natural inclusion S → G and projections G → G / S, A → A_S. We prove it's exact, and that the righthand map is an epimorphism.