Section contents.
Variables (ee: E) (ol: list ee).

Lemma arith_part n (b i j: nat):
(b <= i)%nat -> (i < j)%nat -> (j < b + S n)%nat ->
(2 * / INR (S (j - i)) * INR (i - b) + (1 + (0 + (1 + 2 * / INR (S (j - i)) * INR (b + n - j))))) / INR (S n) = 2 / INR (S (j - i)).