29 lines
635 B
Text
29 lines
635 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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Author: Leonardo de Moura
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-/
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prelude
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import init.fin
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open nat
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definition char := fin 256
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namespace char
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attribute [pattern]
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definition of_nat (n : nat) : char :=
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if H : n < 256 then fin.mk n H else fin.mk 0 dec_trivial
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definition to_nat (c : char) : nat :=
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fin.val c
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end char
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attribute [instance]
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definition char_has_decidable_eq : decidable_eq char :=
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have decidable_eq (fin 256), from _,
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this
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attribute [instance]
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definition char_is_inhabited : inhabited char :=
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inhabited.mk (char.of_nat 65)
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