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Theorems · Definition · group theory

groupCohomology.H1Iso

{k G : Type u} →
  [inst : CommRing k] →
    [inst_1 : Group G] →
      (A : Rep.{u, u, u} k G) → groupCohomology.H1 A ≅ (groupCohomology.shortComplexH1 A).moduleCatLeftHomologyData.H

The 1st group cohomology of A, defined as the 1st cohomology of the complex of inhomogeneous cochains, is isomorphic to cocycles₁ A ⧸ coboundaries₁ A, which is a simpler type.

Defined in
Mathlib.RepresentationTheory.Homological.GroupCohomology.LowDegree
Cited by
3 results in Mathlib
Foundations
Depth 116 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes
CommRingGroup

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