------------------------------------------------------------------------
-- Nullary relations (some core definitions)
------------------------------------------------------------------------

{-# OPTIONS --universe-polymorphism #-}

-- The definitions in this file are reexported by Relation.Nullary.

module Relation.Nullary.Core where

open import Data.Empty
open import Level

-- Negation.

infix 3 ¬_

¬_ :  {}  Set   Set 
¬ P = P  

-- Decidable relations.

data Dec {p} (P : Set p) : Set p where
  yes : ( p :   P)  Dec P
  no  : (¬p : ¬ P)  Dec P