/* Copyright (C) 2020 Daniel Schultz 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 2.1 of the License, or (at your option) any later version. See . */ #include "fmpz_mod.h" int fmpz_mod_is_invertible(const fmpz_t a, const fmpz_mod_ctx_t ctx) { int res; fmpz_t d; fmpz_init(d); fmpz_gcd(d, a, ctx->n); res = fmpz_is_one(d); fmpz_clear(d); return res; }