18 lines
No EOL
653 B
Text
18 lines
No EOL
653 B
Text
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-- 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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-- Author: Leonardo de Moura
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----------------------------------------------------------------------------------------------------
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import logic.connectives.prop
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namespace sum
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inductive sum (A : Type) (B : Type) : Type :=
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| inl : A → sum A B
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| inr : B → sum A B
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infixr `+`:25 := sum
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theorem induction_on {A : Type} {B : Type} {C : Prop} (s : A + B) (H1 : A → C) (H2 : B → C) : C :=
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sum_rec H1 H2 s
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end sum |