∀ {α : Type u} [inst : TopologicalSpace α] {β : Type v} [inst_1 : TopologicalSpace β] [inst_2 : T2Space β]
  [inst_3 : CompactSpace β] {g : α → β} (hg : Continuous g) (a : α), preStoneCechExtend hg (preStoneCechUnit a) = g a