* [homotopy_group](homotopy_group.hlean) (theorems about homotopy groups. The definition and basic facts about homotopy groups is in [algebra/homotopy_group](../algebra/homotopy_group.hlean)).
* [join](join.hlean)
* [hopf](hopf.hlean) (the Hopf construction and delooping of coherent connected H-spaces)
* [complex_hopf](complex_hopf.hlean) (the complex Hopf fibration)
* [imaginaroid](imaginaroid.hlean) (imaginaroids as a variant of the Cayley-Dickson construction)
* [quaternionic_hopf](quaternionic_hopf.hlean) (the quaternionic Hopf fibration)
The following files depend on
[hit.two_quotient](../hit/two_quotient.hlean) which on turn depends on