20 lines
573 B
Text
20 lines
573 B
Text
-- Copyright (c) 2014 Microsoft Corporation. All rights reserved.
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-- Released under Apache 2.0 license as described in the file LICENSE.
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-- Authors: Leonardo de Moura, Jeremy Avigad
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import logic.connectives.basic .inhabited
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using inhabited
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namespace nonempty
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inductive nonempty (A : Type) : Prop :=
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nonempty_intro : A → nonempty A
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definition nonempty_elim {A : Type} {B : Type} (H1 : nonempty A) (H2 : A → B) : B :=
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nonempty_rec H2 H1
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theorem inhabited_imp_nonempty [instance] {A : Type} (H : inhabited A) : nonempty A :=
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nonempty_intro (default A)
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end nonempty
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