 [], [], bytesOut) $ \(r,w) -&gt; 
     forever $ do
       m  &lt;- readQ r        -- receive a request
       jn &lt;- getJobName m   -- get the job name from the request 
       t  &lt;- mapR reg jn (send2Prov w m)   -- apply job
       unless t $ throwIO $ NoProviderX jn -- throw exception
                                           -- when job is not provided
 where send2Prov w m p = writeAdHoc w (prvQ p) nullType 
                                      (msgHdrs m) $ msgContent m
</pre><p>User applicatio