domain

subdomain -2, -2
   piece 2, -2
   piece 2, 2
   piece -2, 2
   piece -2, -2

   newcomp 1, 0
   piece 0, -1
      arc -1
   piece -1, 0
      arc -1
   piece 0, 1
      arc -1
   piece 1, 0
      arc -1

enddomain

graf 1
h 0.2
mesh
pigra
flipdiag

drawdomain
drawmesh