Exercise 1: solutions

module CS410.Sol01 where

open import CS410.Prelude
open import CS410.Lec01

+-assoc : ∀ l m n → (l + m) + n ≡ l + (m + n)
+-assoc zero    m n = refl
+-assoc (suc l) m n = cong suc (+-assoc l m n)