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/*
Copyright (C) 2008, Peter Shrimpton
Copyright (C) 2009 William Hart
Copyright (C) 2014 Dana Jacobsen
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 "ulong_extras.h"
int
n_is_strong_probabprime2_preinv(ulong n, ulong ninv, ulong a,
ulong d)
{
ulong t = d;
ulong y;
FLINT_ASSERT(a < n);
if (a <= 1 || a == n - 1)
return 1;
y = n_powmod2_ui_preinv(a, t, n, ninv);
if (y == UWORD(1))
return 1;
t <<= 1;
while ((t != n - 1) && (y != n - 1))
{
y = n_mulmod2_preinv(y, y, n, ninv);
t <<= 1;
}
return (y == n - 1);
}