1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
/*
Copyright (C) 2020 Fredrik Johansson
This file is part of FLINT.
FLINT is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 3 of the License, or
(at your option) any later version. See <https://www.gnu.org/licenses/>.
*/
#include "ca.h"
truth_t
ca_check_is_neg_i(const ca_t x, ca_ctx_t ctx)
{
if (CA_IS_SPECIAL(x))
{
if (ca_is_unknown(x, ctx))
return T_UNKNOWN;
return T_FALSE;
}
else if (CA_IS_QQ(x, ctx))
{
return T_FALSE;
}
else if (CA_IS_QQ_I(x, ctx))
{
const fmpz *n, *d;
n = QNF_ELEM_NUMREF(CA_NF_ELEM(x));
d = QNF_ELEM_DENREF(CA_NF_ELEM(x));
if (fmpz_is_one(d) && fmpz_is_zero(n) && fmpz_equal_si(n + 1, -1))
return T_TRUE;
return T_FALSE;
}
else
{
truth_t res;
ca_t t;
ca_init(t, ctx);
ca_i(t, ctx);
ca_neg(t, t, ctx);
res = ca_check_equal(x, t, ctx);
ca_clear(t, ctx);
return res;
}
}