avoid empty input and its adverse effect on socket communication, e.g. output message getting "stuck" after vacuous update due to Session.update_options;
avoid empty input and its adverse effect on socket communication, e.g. output message getting "stuck" after vacuous update due to Session.update_options;

MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle,MerelyAPseudonym/isabelle