Hopf problem: homology of x · threefold homology star coproduct

Supporting definitions and proofs for this stage of the six-sphere construction.

theorem Mathoverflow1973.ThreefoldHomologyStarCoproduct.homologyFiniteBiproducts : CategoryTheory.Limits.HasFiniteBiproducts (ChainComplex (ModuleCat ℤ) ℕ)