English
The extension of a continuous g along preStoneCechUnit is equal to g on the base space: preStoneCechExtend hg ∘ preStoneCechUnit = g.
Русский
Расширение непрерывной g по preStoneCechUnit совпадает с g на базовом пространстве: preStoneCechExtend hg ∘ preStoneCechUnit = g.
LaTeX
$$$preStoneCechExtend\; hg \circ preStoneCechUnit = g$$$
Lean4
/-- The extension of a continuous function from `α` to a compact
Hausdorff space `β` to the pre-Stone-Čech compactification of `α`. -/
def preStoneCechExtend : PreStoneCech α → β :=
Quot.lift (Ultrafilter.extend g) fun _ _ ⟨_, hF, hG⟩ ↦ preStoneCechCompat hg hF hG