The Periodic_3_mesh_3 package generates periodic 3-dimensional
isotropic simplicial meshes. The discretized region
may be a monodomain, i.e. a single connected component,
or  a multidomain subdivided into different subdomains.
The domain is input as an oracle able to answer
different types of queries on the domain.
In the current version, Periodic_3_mesh_3 generates meshes for domains described
through implicit functions.
The output is a periodic 3D mesh of the domain volume
and conformal surface meshes for all the boundary and subdividing
surfaces.
