English
For finsupps f,g over a canonically ordered additive structure, Disjoint f g is equivalent to Disjoint f.support g.support.
Русский
Для функций FinSupp f,g над канонически упорядоченным аддитивным набором, Disjoint f g эквивалентно Disjoint supp(f) supp(g).
LaTeX
$$$\\operatorname{Disjoint}(f,g) \\iff \\operatorname{Disjoint}(f.\\operatorname{support}, g.\\operatorname{support})$$$
Lean4
nonrec theorem disjoint_iff {f g : ι →₀ α} : Disjoint f g ↔ Disjoint f.support g.support := by
classical
rw [disjoint_iff, disjoint_iff, Finsupp.bot_eq_zero, ← Finsupp.support_eq_empty, Finsupp.support_inf]
rfl