/- Copyright (c) 2016 Microsoft Corporation. All rights reserved. Released under Apache 2.0 license as described in the file LICENSE. Author: Leonardo de Moura -/ prelude import init.logic theorem unit_eq (a b : unit) : a = b := unit.rec_on a (unit.rec_on b rfl) theorem unit_eq_unit (a : unit) : a = () := unit_eq a () definition unit_subsingleton [instance] : subsingleton unit := subsingleton.intro unit_eq definition unit_is_inhabited [instance] : inhabited unit := inhabited.mk ()