module 0Trinitarianism.Quest1Solutions where open import 0Trinitarianism.Preambles.P1 isEven : ℕ → Type isEven zero = ⊤ isEven (suc zero) = ⊥ isEven (suc (suc n)) = isEven n existsEven : Σ ℕ isEven existsEven = 4 , tt _×_ : Type → Type → Type A × C = Σ A (λ a → C) div2 : Σ ℕ isEven → ℕ div2 (0 , tt) = 0 div2 (suc (suc n) , hn) = suc (div2 (n , hn))