Hopf problem: homology of x · threefold gluing 2 #
Supporting definitions and proofs for this stage of the six-sphere construction.
theorem
Mathoverflow1973.ThreefoldGluing.Data.secondCountableSpace_of_compactBase
{B : Type u}
[TopologicalSpace B]
(D : Data B)
[CompactSpace B]
[∀ (i : D.J), SecondCountableTopology ↑(D.piece i)]
: