specification SERVICE [PUT, GET] :noexit

 library SERVICE endlib

 behaviour

   SERVICE_BODY [PUT, GET]

   where

(* ----------------------------------------------------------------- *)

   process SERVICE_BODY [PUT, GET] : noexit :=

      PUT ?M:MSG;               (* acquiring a new message *)
         GET !M;                (* output the message      *)
            SERVICE_BODY [PUT, GET]

   endproc

(* ----------------------------------------------------------------- *)

endspec