English
Same as Map-Bind above: map f (bind m n) = bind m (λ a, map f (n a)).
Русский
То же самое: map f (bind m n) = bind m (λ a, map f (n a)).
LaTeX
$$$\\mathrm{map}\\, f\\,(\\mathrm{bind}\\, m\\, n) = \\mathrm{bind}\\, m (\\lambda a. \\mathrm{map}\\, f\\,(n\\, a))$$$
Lean4
theorem bind_map (m : Multiset α) (n : β → Multiset γ) (f : α → β) : bind (map f m) n = bind m fun a => n (f a) :=
Multiset.induction_on m (by simp) (by simp +contextual)