24 lines
431 B
Coq
24 lines
431 B
Coq
From mathcomp Require Import all_ssreflect.
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Fixpoint twice (n: nat): nat :=
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if n is n'.+1 then (twice n').+2 else 0.
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Lemma twiceDouble: forall n:nat,
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twice (2 * n) = twice n + twice n.
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Proof.
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elim=> [|n IHn].
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- done.
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- rewrite !addSn.
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rewrite -/twice.
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rewrite mulnS.
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rewrite -IHn.
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Abort.
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Context (A B C: Prop).
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Lemma HilbertS: (A -> B -> C) -> (A -> B) -> A -> C.
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Proof.
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move=> Habc Hab.
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move: Habc.
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