#npoints
2
#ndimensions
1
#nfaces
2
#nfacetypes
1
#points
 -3, 0, 0
  3, 0, 0
#normals
 -1, 0, 0 
  1, 0, 0 
#faces
 1,2
#face_types
 1,1
#area_elements
"1./(6.*dA)"