lean2/library/standard/data/option.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
----------------------------------------------------------------------------------------------------
import logic.classes.inhabited
inductive option (A : Type) : Type :=
| none {} : option A
| some : A → option A
theorem inhabited_option [instance] (A : Type) : inhabited (option A) :=
inhabited_intro none