English
Disjointness is preserved under passage to sets via conversion between finsets and sets: Disjoint (s.toSet) (t.toSet) iff Disjoint s t.
Русский
Не пересечение сохраняется при переходе между конечными множествами и их множествами: Disjoint (s.toSet) (t.toSet) ⇔ Disjoint s t.
LaTeX
$$$\\operatorname{Disjoint}(s^{toSet}, t^{toSet}) \\iff \\operatorname{Disjoint}(s,t)$$$
Lean4
@[simp, norm_cast]
theorem disjoint_coe : Disjoint (s : Set α) t ↔ Disjoint s t := by
simp only [Finset.disjoint_left, Set.disjoint_left, mem_coe]