1 /*
2     Copyright (C) 2011 Fredrik Johansson
3 
4     This file is part of FLINT.
5 
6     FLINT is free software: you can redistribute it and/or modify it under
7     the terms of the GNU Lesser General Public License (LGPL) as published
8     by the Free Software Foundation; either version 2.1 of the License, or
9     (at your option) any later version.  See <http://www.gnu.org/licenses/>.
10 */
11 
12 #include <stdlib.h>
13 #include "flint.h"
14 #include "fmpz_poly.h"
15 #include "fmpz_poly_mat.h"
16 
17 int
fmpz_poly_mat_is_one(const fmpz_poly_mat_t A)18 fmpz_poly_mat_is_one(const fmpz_poly_mat_t A)
19 {
20     slong i, j;
21 
22     if (A->r == 0 || A->c == 0)
23         return 1;
24 
25     for (i = 0; i < A->r; i++)
26     {
27         for (j = 0; j < A->c; j++)
28         {
29             if (i == j)
30             {
31                 if (!fmpz_poly_is_one(fmpz_poly_mat_entry(A, i, j)))
32                     return 0;
33             }
34             else
35             {
36                 if (!fmpz_poly_is_zero(fmpz_poly_mat_entry(A, i, j)))
37                     return 0;
38             }
39         }
40     }
41 
42     return 1;
43 }
44