English
If ι is a Preorder, and each β i is LT and densely ordered, then the colef-lex order on ∀ i, β i is densely ordered.
Русский
Если ι — предорядок, а для каждого i β i LT и плотно упорядован, то Colex (∀ i, β i) плотно упорядован.
LaTeX
$$$[\text{Preorder } \iota] \land [\forall i, LT(\beta i)] \land [\forall i, DenselyOrdered(\beta i)] \Rightarrow \ DenselyOrdered(\mathrm{Colex}(\forall i,\beta i))$$$
Lean4
instance [Preorder ι] [∀ i, LT (β i)] [∀ i, DenselyOrdered (β i)] : DenselyOrdered (Colex (∀ i, β i)) :=
inferInstanceAs (DenselyOrdered (Lex (∀ i : ιᵒᵈ, β (OrderDual.toDual i))))