Boundary physical curves disappear after BooleanFragments
I am modelling a surface, assumed to represent the semi-infinite space for the ground. The edges (left, right, bottom) are marked as Physical Curves, so as to identify them later and assign boundary conditions. The surface may consist of more than one medium (Physical Surface). Within the surface there is a Line element. The mesh is obtained using BooleanFragments, so as to ensure compatibility of the Line element with the surface elements. Unfortunately, after using BooleanFragments the Physical Curves assumed to represent the boundaries disappear. How can I keep them?