no goals
α : Type u_1
s : Finset α
f : α → ℕ
a b : α
n : ℕ
inst✝ : DecidableEq α
h : a ≠ b
⊢ multinomial {a, b} f = choose (f a + f b) (f a)
simp [binomial_eq _ h, choose_eq_factorial_div_factorial (Nat.le_add_right _ _)]