English
The supremum of applying a chain of continuous endomorphisms to a supremum equals the product of the supremum of a zip of chains.
Русский
Предел объединения применения цепи непрерывных отображений к верхнему пределу совпадает с верхним пределом произведения цепей.
LaTeX
$$$\omegaSup\,c_0\,(\omegaSup\,c_1) = \mathrm{Prod}.\ \mathrm{apply}\ (\omegaSup\,(c_0\,\mathrm{zip}\,c_1))$$$
Lean4
/-- The application of continuous functions as a continuous function. -/
@[simps]
def apply : (α →𝒄 β) × α →𝒄 β where
toFun f := f.1 f.2
monotone' x y
h := by
dsimp
trans y.fst x.snd <;> [apply h.1; apply y.1.monotone h.2]
map_ωSup'
c := by
apply le_antisymm
· apply ωSup_le
intro i
dsimp
rw [(c _).fst.continuous]
apply ωSup_le
intro j
apply le_ωSup_of_le (max i j)
apply apply_mono
· exact monotone_fst (OrderHom.mono _ (le_max_left _ _))
· exact monotone_snd (OrderHom.mono _ (le_max_right _ _))
· apply ωSup_le
intro i
apply le_ωSup_of_le i
dsimp
apply OrderHom.mono _
apply le_ωSup_of_le i
rfl