Source code on Github
module Test.Anyable where

open import Class.Prelude
open import Class.Anyable
open import Class.Decidable
open import Class.HasOrder

_ : ∃[ x ∈ List ℕ ∋ 1 ∷ 2 ∷ 3 ∷ [] ] x > 0
_ = auto

_ : ∃[ x ∈ just 42 ] x > 0
_ = auto

_ : ∄[ x ∈ nothing ] x > 0
_ = auto