DIM: 2
DIM_OF_WORLD: 2

number of elements: 4  
number of vertices: 5  

element vertices:
0 1 4 
1 2 4  
2 3 4 
3 0 4 

element boundaries:

0 0 1 
0 0 1 
0 0 1 
0 0 1 


vertex coordinates:
 0.0 0.0  
 1.0 0.0
 1.0 1.0
 0.0 1.0
 0.5 0.5

element neighbours:
1 3 -1 
2 0 -1 
3 1 -1 
0 2 -1