23 lines
614 B
Text
23 lines
614 B
Text
/-
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Copyright (c) 2016 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
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-/
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prelude
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import init.fin
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definition unsigned_sz : nat := 4294967296
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definition unsigned [reducible] := fin unsigned_sz
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namespace unsigned
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definition of_nat [coercion] (n : nat) : unsigned :=
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if H : n < unsigned_sz then fin.mk n H else fin.mk 0 dec_trivial
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definition to_nat (c : unsigned) : nat :=
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fin.val c
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end unsigned
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definition unsigned.has_decidable_eq [instance] : decidable_eq unsigned :=
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have decidable_eq (fin unsigned_sz), from _,
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this
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