module Chapter2.IDesc.Examples.Walk where open import Data.Unit open import Data.Nat open import Data.Fin open import Data.Vec open import Data.Product open import Relation.Binary.PropositionalEquality open import Chapter2.IDesc open import Chapter2.IDesc.Fixpoint open import Chapter2.IDesc.Tagged WalkD : tagDesc ℕ WalkD = (1 , (λ n → `var (suc n) `× `1 ∷ [])) , ((λ { zero → 1 ; (suc n) → 1 }) , λ { zero → `1 ∷ [] ; (suc n) → `var n `× `1 ∷ [] }) Walk : ℕ → Set Walk = μ (toDesc WalkD) up : ∀{n} → Walk (suc n) → Walk n up w = ⟨ zero , w , tt ⟩ stop : Walk 0 stop = ⟨ suc zero , tt ⟩ down : ∀{n} → Walk n → Walk (suc n) down w = ⟨ suc zero , w , tt ⟩