/*
Copyright (C) 2021 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"
int
ca_is_cyclotomic_nf_elem(slong * p, ulong * q, const ca_t x, ca_ctx_t ctx)
{
if (CA_IS_SPECIAL(x))
return 0;
if (CA_IS_QQ(x, ctx))
return 0;
if (CA_IS_QQ_I(x, ctx))
{
if (p != NULL) p[0] = 1;
if (q != NULL) q[0] = 4;
return 1;
}
return CA_FIELD_IS_NF(CA_FIELD(x, ctx)) &&
qqbar_is_root_of_unity(p, q, CA_FIELD_NF_QQBAR(CA_FIELD(x, ctx)));
}