To be able to call a servant, you must first create (using save_servant/1) a saved state that is to be run as the servant. Run Prolog on the machine on which the servant is to be run, and load (that is, compile, consult, or assert) everything that the servant will need. Then call save_servant(SavedState), where SavedState is the name of the file in which to save the state. (This saved state should not normally be started directly from a terminal by a user; when started it will automatically try to open and read a socket.)