Enter an option [Fixcrvsu Delallu eXitl:
Fixcrvsu - Fixes the network of S-polygons and proceeds to GD type 'frame of B-curves on a network of S-polygons (V_3D_Mesh)' for creation directive B-curves of B-surface .
Delallu - Removes set of forming B-curves and comes back to GD '3D_Mesh' .
Exit - Exit.