lean2/library/data/unit/insts.lean

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-- Copyright (c) 2014 Microsoft Corporation. All rights reserved.
-- Released under Apache 2.0 license as described in the file LICENSE.
-- Author: Leonardo de Moura
2014-12-01 04:34:12 +00:00
import data.unit.thms logic.subsingleton
open decidable
namespace unit
protected theorem subsingleton [instance] : subsingleton unit :=
subsingleton.intro (λ a b, equal a b)
protected definition is_inhabited [instance] : inhabited unit :=
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inhabited.mk unit.star
protected definition has_decidable_eq [instance] : decidable_eq unit :=
take (a b : unit), inl (equal a b)
end unit