English
For a set s ⊆ α × α, gen(s) is the set of all pairs of Cauchy filters (F,G) such that s ∈ F.business × G.business.
Русский
Для множества s ⊆ α×α множество gen(s) содержит все пары фильтров Коши (F,G) с условием s ∈ F×G.
LaTeX
$$$\\mathrm{gen}(s)=\\{(F,G) : CauchyFilter(\\alpha)\\times CauchyFilter(\\alpha)\\mid s\\in F.1\\times\\! G.1\\}$$$
Lean4
/-- The pairs of Cauchy filters generated by a set. -/
def gen (s : Set (α × α)) : Set (CauchyFilter α × CauchyFilter α) :=
{p | s ∈ p.1.val ×ˢ p.2.val}