INTEGER FUNCTION EXTERNAL_INIT(io,sim,net,act,veh)
      
#include "dyna.inc"
#include "io.inc"
#include "sim.inc"
#include "network.inc"
#include "activity.inc"
#include "vehicle.inc"
      
      RECORD /Io_Data/      io
      RECORD /Sim_Data/     sim
      RECORD /Road_Network/ net
      RECORD /Activity/     act
      RECORD /Vehicle_Data/ veh(NU_VE)
      
      ! no externals by default
      
      EXTERNAL_INIT=0

      RETURN
      END

      INTEGER FUNCTION EXTERNAL_POST_LINK_HOOKS(io,sim,net,lnum)
      
#include "dyna.inc"
#include "io.inc"
#include "sim.inc"
#include "network.inc"

      RECORD /Io_Data/      io
      RECORD /Sim_Data/     sim
      RECORD /Road_Network/ net
      INTEGER lnum
      
      EXTERNAL_POST_LINK_HOOKS=0
      
      RETURN
      END
      
      
      INTEGER FUNCTION EXTERNAL_PRE_STEP_HOOKS(io,sim,net,act,veh)
      
#include "dyna.inc"
#include "io.inc"
#include "sim.inc"
#include "network.inc"
#include "activity.inc"
#include "vehicle.inc"
      
      RECORD /Io_Data/      io
      RECORD /Sim_Data/     sim
      RECORD /Road_Network/ net
      RECORD /Activity/     act
      RECORD /Vehicle_Data/ veh(NU_VE)
      
      EXTERNAL_PRE_STEP_HOOKS=0

      RETURN
      END
      
      
      
      INTEGER FUNCTION EXTERNAL_POST_STEP_HOOKS(io,sim,net,act,veh)

      
#include "dyna.inc"
#include "io.inc"
#include "sim.inc"
#include "network.inc"
#include "activity.inc"
#include "vehicle.inc"
      
      RECORD /Io_Data/      io
      RECORD /Sim_Data/     sim
      RECORD /Road_Network/ net
      RECORD /Activity/     act
      RECORD /Vehicle_Data/ veh(NU_VE)

      EXTERNAL_POST_STEP_HOOKS=0

      RETURN
      END
      

      
      
      INTEGER FUNCTION EXTERNAL_VEH_EXIT_HOOKS(io,sim,net,act,veh)
      
#include "dyna.inc"
#include "io.inc"
#include "sim.inc"
#include "network.inc"
#include "activity.inc"
#include "vehicle.inc"
      
      RECORD /Io_Data/      io
      RECORD /Sim_Data/     sim
      RECORD /Road_Network/ net
      RECORD /Activity/     act
      RECORD /Vehicle_Data/ veh

      EXTERNAL_VEH_EXIT_HOOKS=0

      RETURN
      END