English
Disjointness is preserved under converting multisets to finite sets: Disjoint m1.toFinset m2.toFinset ⇔ Disjoint m1 m2.
Русский
Не пересечение сохраняется при переходе из много множеств в конечные множества: Disjoint m1.toFinset m2.toFinset ⇔ Disjoint m1 m2.
LaTeX
$$$\\operatorname{Disjoint}(m_1^{\\!toFinset}, m_2^{\\!toFinset}) \\iff \\operatorname{Disjoint}(m_1, m_2)$$$
Lean4
@[simp]
theorem disjoint_toFinset {m1 m2 : Multiset α} : _root_.Disjoint m1.toFinset m2.toFinset ↔ Disjoint m1 m2 := by
simp [disjoint_left, Finset.disjoint_left]