-- The actual database
db = db_add_trains [t01, t02, t03, t04, t05, t06, t07, t08, t09, t10]
   . db_add_routes [route_01, route_02, route_03, route_04, route_05]
   $ empty_db
db = db_add_trains [t01, t02, t03, t04, t05, t06, t07, t08, t09, t10]
   . db_add_routes [route_01, route_02, route_03, route_04, route_05]
   $ empty_db
db = db_add_trains [t01, t02, t03, t04, t05, t06, t07, t08, t09, t10]
   . db_add_routes [route_01, route_02, route_03, route_04, route_05]
   $ empty_db