English
If every α_i has compactIccSpace, then the product space ∀ i, α_i has CompactIccSpace.
Русский
Если для каждого i пространство α_i имеет CompactIccSpace, то произведение пространств ∀ i, α_i также имеет CompactIccSpace.
LaTeX
$$∀ {ι} {α : ι → Type*}, [∀ i, Preorder (α i)] [∀ i, TopologicalSpace (α i)] [∀ i, CompactIccSpace (α i)], CompactIccSpace (∀ i, α i)$$
Lean4
instance {ι : Type*} {α : ι → Type*} [∀ i, Preorder (α i)] [∀ i, TopologicalSpace (α i)] [∀ i, CompactIccSpace (α i)] :
CompactIccSpace (∀ i, α i) :=
⟨fun {a b} => (pi_univ_Icc a b ▸ isCompact_univ_pi) fun _ => isCompact_Icc⟩