resource cs4()
  optype results_type = (...)
  op request(results_cap: cap results_type; ...)
  const N := 20  # number of client processes
  process client(i := 1 to N)
    op results: results_type
     ...
    send request(results,...)
    # possibly perform some other work
    receive results(...)
     ...
  end
  proc request(results_cap, ...)
    # handle request
    send results_cap(...)
  end
end
