English
Disjoint (S.filter p) (T.filter q) for predicates p,q; in particular, disjointness follows from p and q separation.
Русский
Непересечение (S.filter p) и (T.filter q) для предикатов p,q; в частности, непересечение следует из раздельности p и q.
LaTeX
$$$\\operatorname{Disjoint}(\\operatorname{filter}(p, S), \\operatorname{filter}(q, T))$$$
Lean4
theorem disjoint_filter_filter' (s t : Finset α) {p q : α → Prop} [DecidablePred p] [DecidablePred q]
(h : Disjoint p q) : Disjoint (s.filter p) (t.filter q) :=
by
simp_rw [disjoint_left, mem_filter]
rintro a ⟨_, hp⟩ ⟨_, hq⟩
rw [Pi.disjoint_iff] at h
simpa [hp, hq] using h a