resource helper(id, nap_time : int)
   write("helper", id, "is alive, nap_time=", nap_time)

   process help
      var napping : int
      do true ->
         napping := int(random(1000*nap_time))
         writes("age=", age(), ", helper ", id,
           " is napping for ", napping, "ms\n")
         nap(napping)
      od
   end help
end helper

resource user()
   import helper
   var num_helpers : int := 5, nap_time : int := 3, run_time : int := 60
   getarg(1, num_helpers); getarg(2, nap_time); getarg(3, run_time)

   write("resource user starting,", num_helpers, "helpers,",
      nap_time, "napping time,", run_time, "running time")

   fa i := 1 to num_helpers -> create helper(i, nap_time)
   af
   nap(1000*run_time); write("must stop now"); stop
end user

/* ............... Example compile and run(s)

% sr -o dynamic dynamic.sr
% ./dynamic 4 2 5
resource user starting, 4 helpers, 2 napping time, 5 running time
helper 1 is alive, nap_time= 2
age=24, helper 1 is napping for 396ms
helper 2 is alive, nap_time= 2
age=37, helper 2 is napping for 438ms
helper 3 is alive, nap_time= 2
age=53, helper 3 is napping for 1674ms
helper 4 is alive, nap_time= 2
age=66, helper 4 is napping for 365ms
age=429, helper 1 is napping for 1042ms
age=441, helper 4 is napping for 1076ms
age=481, helper 2 is napping for 947ms
age=1439, helper 2 is napping for 1837ms
age=1479, helper 1 is napping for 1916ms
age=1529, helper 4 is napping for 1709ms
age=1739, helper 3 is napping for 829ms
age=2571, helper 3 is napping for 1435ms
age=3249, helper 4 is napping for 8ms
age=3269, helper 4 is napping for 1702ms
age=3290, helper 2 is napping for 1089ms
age=3399, helper 1 is napping for 1628ms
age=4019, helper 3 is napping for 817ms
age=4389, helper 2 is napping for 312ms
age=4710, helper 2 is napping for 822ms
age=4951, helper 3 is napping for 600ms
age=4979, helper 4 is napping for 1737ms
age=5039, helper 1 is napping for 1777ms
must stop now
                                              */