40 lines
947 B
C
40 lines
947 B
C
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/*
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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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#include "util/numerics/mpz.h"
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#include "kernel/environment.h"
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namespace lean {
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/**
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\brief Return true iff the environment \c env contains the following declarations
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in the namespace 'num'
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one : pos_num
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bit0 : pos_num -> pos_num
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bit1 : pos_num -> pos_num
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zero : num
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pos : pos_num -> num
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*/
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bool has_num_decls(environment const & env);
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/**
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\brief Return an expression that encodes the given numeral in binary using
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the declarations one, bit0, bit1, zero, pos.
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\see has_num_decls
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\pre n >= 0
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\post *to_num(from_num(n)) == n
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*/
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expr from_num(mpz const & n);
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/**
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\brief If the given expression encodes a numeral, then convert it back to mpz numeral.
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\see from_num
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*/
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optional<mpz> to_num(expr const & e);
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}
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