mat0  --  Simple matrix.
4	complex
1	1	2	0
1	2	-1	0
2	1	-1	0
2	2	3	0
2	3	-1	0
3	2	-1	0
3	3	3	0
3	4	-1	0
4	3	-1	0
4	4	3	0
0	0	0	0
34	0
0	0
0	0
0	0